I'm a tech, doing these checks everyday to treat every customer the right and honest way.. great training, for my time and the customer's pocket, thank you for the knowledge
Awesome video! I’ve had a scanner for a while but never understood what exactly to look for as far as live data in diagnosing my problem. Thank you for your time!
Incredibly informative material here, brother! First-class all the way! I have been watching videos and clips trying to learn how to read live data for 20+ years still not quite understanding it all. In 14 min you just topped all of the others! Wow! Thank you sir. Outstanding!
Hi thanks for sharing this information because I just bought A scanner obd2 reader for DIY for my ford escape 2004 I was viewing few on utube I just randomly clicked on your videos on how to read what is On the live data on fuel trims & short/ long term work Stogether with o2sensors l have learnt what is happening to my engine efficiency with your calm voice instructions I analyze with better clarity how to diagnose if having problems like vacuum leak all types etc or with fuel related issues so you emphasize things it’s simple but so important to learn I appreciate your help to me & other people search for answers by your videos bring it together for me any way thank you 👍😊 so I subscribe & like as well. Great job 🤙🏽
Awesome, was looking at the live data the other day for a p0141 on a rav4, and you are correct not a lot of good content exists, so thank you and keep'em coming:)
Great video's on live data. I'm new to reading live data and I need some guidance on how to diagnose a high-idle condition on a 2005 Corolla. Idle is around 1,000 RPM and is a quite rough so I assumed a vacuum leak, but I've checked/changed all vacuum hoses and even replaced the MAF sensor and confirmed no manifold or PCV leaks. Since the car is 18 years old (original owner), I've replaced both O2 sensors and all injectors which improved the vibration level, but it is still present. The last thing I did to the car was to clean out the throttle body (there is no IAC valve). Here are some live-date anomalies (at operating temp) after my last repair: SHRTFT = -20.3% (LONG is 5.5%), TP = 14.9% and will not go to zero even though the adjustment is full minimum, O2S11 = 2.914V (S12 is .095V). Do you have any idea what may be causing the rough, high idle?
Love this video and thank you I found my knock sensor that was in my truck but I like the cold air because it makes my car sound good but you are right it doesn't gain any horsepower this is a great video thank you
Thank you. Very informative. My LT Trim is -25% and my buddies got me tracking down a phantom vacuum leak. Now I'm gonna pressure test the fuel system to look for a leaking injector
I had a p0160 b2s2 . I put my scanner on the live data and it was like a constant value. Then I rev the engine a little and then I saw it change some. I ended up jus clearing code since I saw the reading change some after rev the engine some. I had the car idleing some for awhile so as I was working on something dealing with the power steering fluid flush(suck fluid and add 3 times) I’ll keep my eye on this one p0160. B2s2. Great vid on this subject matter
Cold air intake will gain power. A lot of factory ecu are calibrated to be a little richer at wide open throttle, adding the cold air intake leans it out a little and gain power. Closed loop is only used during idle and cruising.
Great video. I have a vehicle that reads: O2 B1S1 .9mv O2 B1S2 .0mv O2 B2S1 .0mv O2 B2S2 1.0mv STFT bank 1 -20% STFT bank 2 30% LTFT bank 1 -4% LTFT bank 2 30% Inj. duty bank 1 4.4msec Inj. duty bank 2 11.5msec
I'd just like to add... In my case, I was getting the 171/174 codes. So instantly thought lean/vacuum issue. So, took a water bottle, and sprayed along the intake manifold along both sides, and sure enough, got the engine to stumble. Replaced the intake gasket, and hooked up the scanner, and during the drive cycle, it thru the check engine light again, with the 174 code. Hooked up a smoke tester, found a cut gasket on the Throttle Body. Then had the smoke tester at 5psi, and saw no visible leaks anywhere, while holding 5psi for several minutes. Reset the computer, and started the drive cycle again. Was watching the fuel trims again, and the long terms kept going higher and higher, and were staying in the 12-15% range through various road conditions, stop/go traffic, up and down hills etc. Then as I was thinking the drive cycle should be completed, it threw the 174 code, AGAIN. So, now I had to change my thinking from "too much air" causing the lean codes, to "not enough fuel"... Because I know there are no vacuum leaks, it has to be on the fuel side. Either clogged fuel filter, kinked fuel line, bad fuel pump etc. So, just wanted to add, that LEAN doesn't always mean "vacuum leak".. it can sometimes mean "not enough fuel"
04 Jeep Liberty 3.7L, 115k got a P0157 bank 2 sensor 2 low voltage a couple weeks ago. Cleared code and hasn’t come back. It got me looking at live data and notice my long term fuel trims are at or around +10 all the time. I couldn’t find any vacuum leaks. My short terms seams close to zero. Little bit of rough idle, more rough when cold. Both cats replaced at 90k by previous owner. No other codes and the P0157 never came back. I don’t hear any exhaust leaks.
Should I be checking theses while idling? My truck seems to be having issues when I am towing and going up hill. No codes, no misfires, took to shop for a trans flush. Dropped pan, all looked good. No metal in pan and fluid wasn’t that dirty. When I punch it, I can feel and hear that my truck is not shifting like it used to, and when I am towing up hill my truck will jump when I’m 1st or 2nd. Once I get pass 2Nd truck seems to run fine. So I have a OBD reader plugged in right now and I am trying to understand the terminology etc. so, when checking my O2 sensors and fuel trim, should I be checking while driving or in idle? Bc when I step on it, my % goes well over 10%. Hope all this makes sense. Thanks for your vids
Basically, yes. Vacuum leaks tend to be persistent, and that likely shows up as positive on LTFT: you'll see that fade to a lower number as throttle body opens most cases, but STFT picks up first. If fuel pressure is to high, or injector metering more than designed [for whatever reason] trim shows up negative. STFT is more of a fine tuning/rapid response - it should be active, as temperatures and manifold air pressure vary during operation, and sensors provide feedback to ECU. LTFT keeps you in workable mixture range [steady state] to allow STFT to nail down air/fuel ratio [changing speeds].
I have a ford explorer right now where I have negative fuel trim on bank one and positive fuel trim on bank two. That's long term fuel trim. My short term is great. This truck came from another shop and I didn't get a straight story of what's been done.
Thanks for the information, I'm no mechanic, trying to fix an Issue I'm having with my Acura TSX 2009, it's giving me error code P0131, changed the spark-plugs, ignition. coils and even fuel injectors, but problem didn't go away. Car doesn't go over 20 mph ad checkengine is blinking. I got Foxwell scanner recently, but not sure what numbers I should be looking for when in comes to O2! SHRTFT1: -31.3, LONGFT1: -3.9, SHRTFTB1S2: -31:3
It sure would be nice if these chinese manuals would elaborate what each of the readings mean past a simple expanded name when you push the ? mark key such as explained in this video. Thank you.
Best video in my opinion took time to explain everything and in laymen terms so a bigginer will understand my question is I noticed this on yours and mine off to side there is a question mark and G what do they mean if anything thanks and again video is the best
Hey, thanks for that man I appreciate it! I have new ones coming soon that go into a lot more detail as well! Some scanners are different but alot of times you can click the question mark and it will tell you more information. Yours may be different though. Thanks for watching!
Excellent Video... much appreciated. I have a 1996 E-150 5.8L EFi . Have ABS light on, OBD2 reader says "This vehicle does not support ABS communication" is that correct ? if so do you know of any other way to identify the faulty sensor (assuming it is a sensor fault) also..... when backing off the throttle the RPM holds, at whatever RPM you were at, for 2 - 3 seconds before dropping.... any ideas ? there is the occasional hickup at idle and sometime it stalls. PCV valve replaced. Any help would be much appreciated. Regards Paul
It sounds like you are saying the cold air intake, bigger intake air hose, or bigger throttle body does not make a difference since the ECU will simply adjust (eg keep the throttle body more closed) to compensate/restrict the extra air intake to keep the same 14.7:1 air to fuel ratio. Correct?
Thank You!! Very informative video.. but what about diagnosing faulty OSS or (Output Speed Sensor) on Transmission 4.6L? I've already wasted money replacing it with 3 different ones.. still having code, and engine light, and O/D light blinking!! Wires all seem to look fine.
I have a 2014 Jeep JK that has had a small engine surge while going down road. At idle, not detected. Least surge is not detected on tach, the up/down is so quick, really doesn’t have time to register. Worst cases, while going up a hill around 35-40mph, by ear it is swinging much more and you can see on tach that it is 50-75 rpm fluctuations. No codes at all. Looking at o2 sensors and fuel trims after engine is in op temp but at idle, o2 upstreams are bouncing all over 75mv up to 800+. Again it is so quick, can not grab a solid number. Downstream sensors however, b1s2 sits around 250mv while b2s2 is around 685mv. While these o2 readings are taking place, fuel trims stftb1, stftb2 and ltftb2 are bouncing between .0 and -3.9. Ltftb1 sits at 0, no movement. It will change when revved up, but still not hanging near where the others are going. Could b1s2 o2 sensor be going out? Could that cause my surge? Shops I have taken it to say no code, no problem without looking at it to see what I’m hearing and seeing. 84k miles on engine and first issues I’ve had. Owned since new.
Got P0171 lean bank 1 on 03 S10 2.2 engine , LTFT at 1100 rpm 21.9. STFT 3.1. No vacuum leaks , would you have any ideas ? Thanks , I have 18lbs of vacuum at idle
Thanks for the great video. Helped a lot. I have a problem you didn't cover hoping you could answer for me. My STFT B1 S2 is 99.2 and my STFT B1S1 is - 63. If you could tell me what that is. And what's causing the 99.2. It never changes it like it is stuck. Thanks
Just seeing this sorry, I hope you got it figured out. 9 times out of 10 a maxed out fuel trim (99%) is caused by a bad 02 sensor. See what they're reading. Alot of times when you see the fuel trim at 99 you'll have an 02 sensor not really reading much, no change or super laggy and barely moving at all. Again sorry for the late response.
These values while the car is not moving, idle, what happens when you step on the gas or open the throttle? How much should the short and long fule trim be???
what does it mean if both my o2b1s1 and o2b1s2 go to a steady 0.20 (could be 0.020 i forget, but point is it's steady and will have pending code) when the fan or stereo is on? when i turn both off, those sensors seem to fluctuate again. also, are the o2 sensors supposed to go to steady value like i mentioned in park? all my o2 sensors (2 banks 2 sensors each) drop to a steady 0.20 or 0.40 in park. or is that a function of not being in closed loop like you mentioned, because i didnt let my bank 1 sensors run long enough (because of the stereo or fan being on)?
Thanks for the video. I ran the OBD on my car, monitored values real time and found that my bank 1 sensor 1 and bank 2, sensor 1 are showing values between 4% and -4%. However, bank 1 sensor 2 and bank 2 sensor 2 are both stuck at 99.22%. Getting P2096 code after I got the shop to install the complete catback solo exhaust. What's your take on this? Can't be the sensors going bad. I am assuming they didnt plug it in properly etc....
I have a 2001 chevy prizm 1.8 toyota vvt , (no i or 4 , different engines). Should the readings be the same where the O2 sensors or air/ fuel sensor and fuel trim readings are concerned? Thanks. J.
Thank you for the information, I have a Toyota corolla LE 2012 and I failed the smog test because of 02 sensor and cat but my car did not show any code also I follow a Toyota drive cycle and I drove 360miles highway 55 t0 60 after I slow down without using break just helping the car with hand break to 35-45 but still not ready! but when I plugged my OBD2 IT SHOW THAT MY O2S1 bank1 (V)=3.306 AND O2S1BANK2 (V)= 0.660 the car was warmed up for more than 10 min ! please do I need to change both 02 and after drive it probably it will make the car ready for emission! thank you very much
Hey. Superb video. I have strange problem with short fuel trims. My engine is BMW M54B30. On bank 1 i got +25-28%, but on bank 2 it is ok 0 to 5%. I know that my oxygen sensor after cat on bank1 is dead. Is this can affect on fuel trims? MAF is working, I checked rubber hoses and there is no cracks. Help please. Thanks.
Great video I have a 1997 suburban 454 3out if the 4 o2s are reading 700ish MV and long term fuel both banks is +9 do you think my o2s are bad? ThNk you for any advice...
My 97 tacoma 2.7 is running at +13 long term fuel trim running at highway speeds and my short term fluctuating between + and -. My 02 sensor is hanging at 0.135v. Would those numbers suggest a lean condition pointing towards weak fuel delivery?
Thanks, watched video twice. So understand how its all goes together. ? My shortT reading -17. Longt 0.0 so how I'm understanding my issue is not vacuum leaks. Itd a fuel issue. . so my ? Is I have been putting fuel injector cleaner and its not that. So I'm gonna go with a fuel injector is clogged ? So I would have to basically clean all of them because I don't know what fuel injector is they don't label which one would be the one bad right? Thank you so much for your help. I so understand how it works. So what would I do next do I put maybe a direct cleaner to the fuel injectors or do I have to clean each one by hand which I don't even know how to do I'm going to touch them before and I'm a female mechanic for 25 yes. You and wiring electrical was not my thing though I so confused with injectors does this but if you could like give me a little push or something what should I look for I mean what should I do for the injectors and if it doesn't clear up see my fuel pump was a new fuel pump was put in like I want to say maybe a year and a half ago. I'm leaning more towards of fuel injector clogged I think thank you again have a great night
Thank you for the video I picked up A lot of knowledge I have a 2006 Audi S4 4.2 and the problem I’ve been having is with the long term fuel trim bank one is usually lower than bank two sometimes bank one goes up to 8 to 9 on positive as bank two stays around eight and then shoots up to 12 my mechanic and I have looked at everything we didn’t fine no leaks through the intake , maf or any of the vacuum lines and then every 6 to 7 days I get P0492 P0171 and P0174 lean codes what do you recommend will be the next thing to check for go to be maybe I have bad O2 sensors or could it be coming from the exhaust I’m so frustrated trying to find the problem of this issue also I get a little rough idle on standstill as well other than that the car runs great on highway and on full speed. Please let me know your input would be very valuable Also forgot to mention 02 oxygen sensor on bank two reads 0.00 doesn’t move
Hey great video but I got a question that will stump you.2001 mustang v6 305k miles cats went out .I replaced the factory cats with flowmaster universal and made basically a entire pipe and 2 new downstream o2 sensors.but at idle my b1s2 reads .060 on average b2s2 is at the same but will go up and fluctuate a few times and back down to around .060...do you tft think I may just have the wrong or defective o2 sensors .Car runs great no power loss or smoke.front o2 sensors read like they should .hasn't thrown any codes but won't complete catalysts monitor.
2016 Sonata Hybrid 151k miles Idling in Maint mode after 20 mile drive Smooth idle No power loss No mpg loss No rotten egg smell Some lifter noise at slow speed, light accelerator, uphill before gearing down. P0420 New 02 sensor on Bank1 S1 (cat is in manifold) Sensor 2 (in front of lower cat) is factory. Any ideas would be greatly appreciated. 👍 STFT 15.6% LTFT -32.0 02S12 (V) = .790 V 02S11 (mA) 0 to -.05 STSO2FT1 -1.6% LGSO2FT1 3.1% CATTEMP11 (576 Celsius) CATTEMP12 (400 Celsius) LAMBDA11 0.998 ish LAMBDA 0.999 ish
Got negative ten long term fuel trims a touch higher on bank 1...a bit low o2 sensor readings on upstream...Maf reading at about 4.3...2001 nissan sentra gxe with the 1.8...runs pretty good but a little rough on the idle...cleaned throttle body and iac...experimented with the egr...any ideas?
got a 09 qx56 infinity, longft1 -3.9 shortft1 -3.9 longft2 -7.0 shorth ft2 3.1 02B1S1 2.47 02B3S1 2.255 02B3S2 0.080 02B1S2 0.050, getting p 0420 code, change bank1 sensor 2 and MAF sensor, CEL stayed off for a day and back on now. took off exhaust bolts and was told CAT looks fine, any advise.
I have a 2004 liberty 3.7 I got two codes, p0132 and p0152 every thing from the pcm to the connectors is okay, I checked resistance in every cable and all are okay, I changed both o2 upstream sensors oem, and still the same keep steady Reading of 1.270 on both o2 Sensors, down stream sensors Reading are weird also, I got 0.035 on both sides sometimes they go up to 0.700 and sometimes the upstreams start to oscilate but for a few seconds. Do you know what can be causing this?
Greetings, I have a suzuki Kizashi 2.4L S. The ecu throws check engine light with p0101 code. The fault code is thrown under 3 conditions: 1. Coasting downhill with zero to minimim accelerator input. (Tps at 19.6 degree, MAF at 10-11g/sec) 2. Cold start after 24+hours in colder environment. Ltft drops down suddenly to -11 to -17% but goes back to 0-3% 3. High rpm idle test. Rpm set at 2.5k, stft increases from +1% to 5% and then returns back to 0%to1%. Can you suggest a way forward? I also have a bad valve cover gasket
Hi how are things ? I have a 2011 Mazdaspeed 3 2.3L Turbocharged with Rich's issues I have the long term fuel trim at sometimes -16, -19,- 17, as the car warms up it becomes more negative, speeding up the long term fuel trim fuel trims, it goes down to -9.50 or sometimes -10.50 could the problem be a vacuum leak, or air leak after the MAF sensor? the short terms always go 0 -0 sometimes +7 but when accelerating sharply sometimes it jumps to crazy numbers like -17 or sometimes +20 what could be the problem friend? I would like to hear the comment
Hey there question, so in the same way learned by doing the work myself cause I couldn't pay someone but I'm lost when it's coming to this 02 to short term trim stuff. I have a shrtftb2s2(%) 99.2 and my longft are at 25. I have replaced my intake gasket and put old but good I believe 02 sensors in and it shows my 02 sensors are working and shrtft are working fine. Where should I go from here? 01 Silverado. Truck runs bad in open loop then better in closed loop but still not like it should. Any help would be great.
In an older car, like a 2000, does the ECU use the downstream sensor for fuel at all? I've heard differing opinions, but most people say the secondary O2 sensor after the cat is just there to determine the health of the cat, and only the primary O2 sensor decides the fuel. I put an 02 sensor spacer in mine to get rid of the P0420 and am wondering if that's messing with my fuel trims at all.
That second o2 sensor is there for correcting air fuel ratio, not health of your cat. Some people put the spacer in to trick the ecm when a bad cat is present. It may very well be your issue.
What if you drive a Ford and no O2 sensor voltage can be displayed? My bi directional tool can only display microamps on the downstream sensor, which is meaningless to me. I CAN see voltage on my GM and Chrysler vehicles. Does Ford use a different data point at the ECU to adjust fueling?
Hello I have a 07 g35x and my long term ban 2 is staying at 35.2 everything else is fine do can you tell me why that’s happening is it a oxygen sensor and how do I figure out which sensor it is I’m also get a code p0174 I’d appreciate your help
Hi, I hope you’re still checking your channel. I have a question on data stream codes. What does it mean when my oxygen sensor codes give me N/A instead of a number. (O2B1S1 N/A) I have a reading for B1S2 but then not B2S1, B2S2, B3S2, B4S1 (all have N/A). BTW thank you for these videos. Could you do more on all these other codes? SPARKADV, MAF, etc
Hello,thank you for the information. I was wondering if you could help me in the right direction? I have an 06 5.7 hemi and I'm getting these codes for Lean fuel mix and I've looked it over and I simply can't find a leak anywhere,it does have an aftermarket intake but I'm not sure if that would be the cause. The Ltft is reading 32% and 21% at idle but they get close to 7% when I'm about 1/3 on the throttle and they return to the previous. I would appreciate your help. Thanks
9.4 fuel trim is a bit high.. 😅 I won't even tell you what mine was then lol I haven't got to figure out my p0171 lean code yet but I think it was because I didn't have an air filter on my cold air because it fit different on my 98 cobra, or i need to plumb the valve cover vent back into the crankcase for positive vacuum because the 98 was a little different that the 01 cobra but it was dumping about 25% on the trim. Luckily im still breaking in the motor so there was no getting in it with those trim levels.
I’m getting a positive ltft reading only on bank 2 I’ve checked and changed almost everything including catalyst converter and still no change sprayed brake clean around the intake as well
Great info. Thank you. But one observation if you don't mind. 10:25 Isn't spraying "soapy water" on the intake leak sucking it into the engine? I'm no mechanic, but I think that's bad.
BANK 2 for me is ~50% STFT! and high LTFT also. I used a smoke machine and found a few intake air vacuum leaks.... but still remained. I used the smoke machine into the TAILPIPE and found a badly leaking exhaust DONUT from the exhaust manifold. $5 fix... will find out tmrw hopefully!
Hi, I'm having an issue with my car idling kinda rough and hesitating especially when pulling away from a stop. I'm kinda new to using live data I just wondered if you have any suggestions what I should be looking for? thanks, cars not throwing any codes so I'm kinda struggling with where to start.
Fuel trims somtimes are not accurate, caused by one the sensors, like mine the MAP sensor cause both fuel trim to be at 12 to 14 percent, i tought i have vacuum leak, but it was the aftemarket delphi MAP senosr reporting wrong values to the ECM, i just put back the OEM sensor and the fuel trim went down to 5 percent. I couldnt believe it, the initiale issue was rought idling and somtimes engine misfire, but it was the ignition electric connection wires were loose at the aftermarket start button system, basically i create the problem overtime by using bad quickdisconnect connector, i replace the connector and problem solved partially rought idle and misfire, but fuel trim problem got fixed by installing OEM MAP sensor back.
Easily the best video on o2s and trim I've seen.
No BS
Straight up knowledge.
Excellent video.
Thank you
I'm a tech, doing these checks everyday to treat every customer the right and honest way.. great training, for my time and the customer's pocket, thank you for the knowledge
Awesome video! I’ve had a scanner for a while but never understood what exactly to look for as far as live data in diagnosing my problem. Thank you for your time!
Very educational.. I'm a diy person and bought a Zurich z8.. now I understand these readings better.
Thank you for teaching me how to read my sensors, you are a life saver. Awesome video.
Exelent explanation on how this o2 sensors work. It might take me 20 times to see this video but you went really well.. Thank you 👍🏻
Incredibly informative material here, brother! First-class all the way! I have been watching videos and clips trying to learn how to read live data for 20+ years still not quite understanding it all. In 14 min you just topped all of the others! Wow! Thank you sir. Outstanding!
Hi thanks for sharing this information because I just bought A scanner obd2 reader for DIY for my ford escape 2004 I was viewing few on utube I just randomly clicked on your videos on how to read what is On the live data on fuel trims & short/ long term work Stogether with o2sensors l have learnt what is happening to my engine efficiency with your calm voice instructions I analyze with better clarity how to diagnose if having problems like vacuum leak all types etc or with fuel related issues so you emphasize things it’s simple but so important to learn I appreciate your help to me & other people search for answers by your videos bring it together for me any way thank you 👍😊 so I subscribe & like as well. Great job 🤙🏽
Very useful brother. I'm working in NISSAN dealer in Dubai. It's much helpful for me.
Bro, this video saved my 2000 F150 w 350k miles on it!!! Thank you sir!!
Awesome, was looking at the live data the other day for a p0141 on a rav4, and you are correct not a lot of good content exists, so thank you and keep'em coming:)
Learning to read my scanner and was wondering what some of the terms and readings were all about, and wow, I found your very informative comments
WoW hat's off sir what a great and deep and easy lecture with live data streaming salute sir
Great video's on live data. I'm new to reading live data and I need some guidance on how to diagnose a high-idle condition on a 2005 Corolla. Idle is around 1,000 RPM and is a quite rough so I assumed a vacuum leak, but I've checked/changed all vacuum hoses and even replaced the MAF sensor and confirmed no manifold or PCV leaks. Since the car is 18 years old (original owner), I've replaced both O2 sensors and all injectors which improved the vibration level, but it is still present. The last thing I did to the car was to clean out the throttle body (there is no IAC valve). Here are some live-date anomalies (at operating temp) after my last repair: SHRTFT = -20.3% (LONG is 5.5%), TP = 14.9% and will not go to zero even though the adjustment is full minimum, O2S11 = 2.914V (S12 is .095V). Do you have any idea what may be causing the rough, high idle?
Smoke test
Love this video and thank you I found my knock sensor that was in my truck but I like the cold air because it makes my car sound good but you are right it doesn't gain any horsepower this is a great video thank you
Good video bro. I've been twisting wrenches for yrs,but I needed to understand my live data.👍
The point you made about the cold air is true. If you change the air fuel ratio outside of factory you'll need a tune.
Thank you. Very informative. My LT Trim is -25% and my buddies got me tracking down a phantom vacuum leak. Now I'm gonna pressure test the fuel system to look for a leaking injector
Mark Dziamski hey did u find the problem minds is -3.1
@@jarademajor8401 -3.1 is perfectly normal !
one of my short terms is + 25
Sounds like you got a stuck open injector.
Your buddies are exactly wrong. -25 means the mixture is extremely rich. That's not a vacuum leak. It is the exact opposite.
Love the explanation. My Camry stft 0.0. And ltft 38.9. I change maf and 02 sensors also done smoke test
Perfect, the way you explain 👌👌👌👌👌
All the way from south africa
You're a great teacher lets get this guy more subscribers
Hey man I seriously appreciate that! More videos coming very soon!
Bro..... great video. Please keep em coming. Best descriptive video ive seen in a long time
This is an incredible video !!! Amazing explanation on live data
i'm starting to understand this whole thing.Thanks man
Great video bro, good way to explain everything in easy terms to understand
I had a p0160 b2s2 . I put my scanner on the live data and it was like a constant value. Then I rev the engine a little and then I saw it change some.
I ended up jus clearing code since I saw the reading change some after rev the engine some. I had the car idleing some for awhile so as I was working on something dealing with the power steering fluid flush(suck fluid and add 3 times)
I’ll keep my eye on this one p0160. B2s2. Great vid on this subject matter
One hell of an informative video.
It’s very good explanation video, Make me more understanding about the STFT and LTFT Thank you
Cold air intake will gain power. A lot of factory ecu are calibrated to be a little richer at wide open throttle, adding the cold air intake leans it out a little and gain power. Closed loop is only used during idle and cruising.
Thanks man for clarifying these readings, so useful!!
Thank you sir. I am having about 28 positive at longtrim. I will check for a air leaking somewhere .
Your doing a good job keeping us informed thank you
Great video. I have a vehicle that reads:
O2 B1S1 .9mv
O2 B1S2 .0mv
O2 B2S1 .0mv
O2 B2S2 1.0mv
STFT bank 1 -20%
STFT bank 2 30%
LTFT bank 1 -4%
LTFT bank 2 30%
Inj. duty bank 1 4.4msec
Inj. duty bank 2 11.5msec
The zeros should be replaced right
I had the phone plugged into the truck stereo not as noticeable through the phone and laptop. Another good video.
Bob Wolf thank you I appreciate that!
Thank you for ur video I’m new on this subject and new on using a scan tool I appreciate your information and how u cover the information thanks
I'd just like to add...
In my case, I was getting the 171/174 codes. So instantly thought lean/vacuum issue.
So, took a water bottle, and sprayed along the intake manifold along both sides, and sure enough, got the engine to stumble.
Replaced the intake gasket, and hooked up the scanner, and during the drive cycle, it thru the check engine light again, with the 174 code.
Hooked up a smoke tester, found a cut gasket on the Throttle Body.
Then had the smoke tester at 5psi, and saw no visible leaks anywhere, while holding 5psi for several minutes.
Reset the computer, and started the drive cycle again.
Was watching the fuel trims again, and the long terms kept going higher and higher, and were staying in the 12-15% range through various road conditions, stop/go traffic, up and down hills etc. Then as I was thinking the drive cycle should be completed, it threw the 174 code, AGAIN.
So, now I had to change my thinking from "too much air" causing the lean codes, to "not enough fuel"... Because I know there are no vacuum leaks, it has to be on the fuel side. Either clogged fuel filter, kinked fuel line, bad fuel pump etc.
So, just wanted to add, that LEAN doesn't always mean "vacuum leak".. it can sometimes mean "not enough fuel"
interesting hypothesis
You do well on explaining as well diagnosis
Knowledge is great for self taught good job
04 Jeep Liberty 3.7L, 115k got a P0157 bank 2 sensor 2 low voltage a couple weeks ago. Cleared code and hasn’t come back. It got me looking at live data and notice my long term fuel trims are at or around +10 all the time. I couldn’t find any vacuum leaks. My short terms seams close to zero. Little bit of rough idle, more rough when cold. Both cats replaced at 90k by previous owner. No other codes and the P0157 never came back. I don’t hear any exhaust leaks.
Real good explanation of FT.
And that’s why the screen has all that info; makes it easy to understand.
Should I be checking theses while idling? My truck seems to be having issues when I am towing and going up hill. No codes, no misfires, took to shop for a trans flush. Dropped pan, all looked good. No metal in pan and fluid wasn’t that dirty. When I punch it, I can feel and hear that my truck is not shifting like it used to, and when I am towing up hill my truck will jump when I’m 1st or 2nd. Once I get pass 2Nd truck seems to run fine. So I have a OBD reader plugged in right now and I am trying to understand the terminology etc. so, when checking my O2 sensors and fuel trim, should I be checking while driving or in idle? Bc when I step on it, my % goes well over 10%. Hope all this makes sense. Thanks for your vids
Best video.was waiting for the live data on the trims wave forms
Now I finally got a little understanding about this. Thank you..
13:00
STFT POSITIVE adding fuel ~>Vacuum leaks
STFT NEGATIVE taking fuel away ~>Fuel system issues (injectors or fuel pressure regulator) Correct???
Not necessarily. Positive and negative will 0 out +5 short and -5 long means 0
Basically, yes. Vacuum leaks tend to be persistent, and that likely shows up as positive on LTFT: you'll see that fade to a lower number as throttle body opens most cases, but STFT picks up first. If fuel pressure is to high, or injector metering more than designed [for whatever reason] trim shows up negative. STFT is more of a fine tuning/rapid response - it should be active, as temperatures and manifold air pressure vary during operation, and sensors provide feedback to ECU. LTFT keeps you in workable mixture range [steady state] to allow STFT to nail down air/fuel ratio [changing speeds].
I have a ford explorer right now where I have negative fuel trim on bank one and positive fuel trim on bank two. That's long term fuel trim. My short term is great. This truck came from another shop and I didn't get a straight story of what's been done.
Thanks for the information, I'm no mechanic, trying to fix an Issue I'm having with my Acura TSX 2009, it's giving me error code P0131, changed the spark-plugs, ignition. coils and even fuel injectors, but problem didn't go away. Car doesn't go over 20 mph ad checkengine is blinking. I got Foxwell scanner recently, but not sure what numbers I should be looking for when in comes to O2!
SHRTFT1: -31.3, LONGFT1: -3.9, SHRTFTB1S2: -31:3
It sure would be nice if these chinese manuals would elaborate what each of the readings mean past a simple expanded name when you push the ? mark key such as explained in this video. Thank you.
Best video in my opinion took time to explain everything and in laymen terms so a bigginer will understand my question is I noticed this on yours and mine off to side there is a question mark and G what do they mean if anything thanks and again video is the best
Hey, thanks for that man I appreciate it! I have new ones coming soon that go into a lot more detail as well! Some scanners are different but alot of times you can click the question mark and it will tell you more information. Yours may be different though. Thanks for watching!
Thanks for making this video. It helps me a lot. What numbers patterns indicate O2 sensor is bad? Like, number not moving like your sensor 2?
Excellent Video... much appreciated. I have a 1996 E-150 5.8L EFi . Have ABS light on, OBD2 reader says "This vehicle does not support ABS communication" is that correct ? if so do you know of any other way to identify the faulty sensor (assuming it is a sensor fault) also..... when backing off the throttle the RPM holds, at whatever RPM you were at, for 2 - 3 seconds before dropping.... any ideas ? there is the occasional hickup at idle and sometime it stalls. PCV valve replaced. Any help would be much appreciated. Regards Paul
Very well explained great video help me out thank you
Great video!!! Very explanatory! So I been dealing with an issue where my cat fuel trims aren't moving and my bank 1 sensor 1 is reading no voltage
It sounds like you are saying the cold air intake, bigger intake air hose, or bigger throttle body does not make a difference since the ECU will simply adjust (eg keep the throttle body more closed) to compensate/restrict the extra air intake to keep the same 14.7:1 air to fuel ratio. Correct?
Thank You!! Very informative video.. but what about diagnosing faulty OSS or (Output Speed Sensor) on Transmission 4.6L? I've already wasted money replacing it with 3 different ones.. still having code, and engine light, and O/D light blinking!! Wires all seem to look fine.
thanks very very very clear & clean message easy for understanding be cause the way you talk slowly quite really nice way awesome again i say thnks
I have a 2014 Jeep JK that has had a small engine surge while going down road. At idle, not detected. Least surge is not detected on tach, the up/down is so quick, really doesn’t have time to register. Worst cases, while going up a hill around 35-40mph, by ear it is swinging much more and you can see on tach that it is 50-75 rpm fluctuations. No codes at all. Looking at o2 sensors and fuel trims after engine is in op temp but at idle, o2 upstreams are bouncing all over 75mv up to 800+. Again it is so quick, can not grab a solid number. Downstream sensors however, b1s2 sits around 250mv while b2s2 is around 685mv. While these o2 readings are taking place, fuel trims stftb1, stftb2 and ltftb2 are bouncing between .0 and -3.9. Ltftb1 sits at 0, no movement. It will change when revved up, but still not hanging near where the others are going. Could b1s2 o2 sensor be going out? Could that cause my surge? Shops I have taken it to say no code, no problem without looking at it to see what I’m hearing and seeing. 84k miles on engine and first issues I’ve had. Owned since new.
Got P0171 lean bank 1 on 03 S10 2.2 engine , LTFT at 1100 rpm 21.9. STFT 3.1. No vacuum leaks , would you have any ideas ? Thanks , I have 18lbs of vacuum at idle
Thanks for the great video. Helped a lot. I have a problem you didn't cover hoping you could answer for me. My STFT B1 S2 is 99.2 and my STFT B1S1 is - 63. If you could tell me what that is. And what's causing the 99.2. It never changes it like it is stuck. Thanks
Just seeing this sorry, I hope you got it figured out. 9 times out of 10 a maxed out fuel trim (99%) is caused by a bad 02 sensor. See what they're reading. Alot of times when you see the fuel trim at 99 you'll have an 02 sensor not really reading much, no change or super laggy and barely moving at all. Again sorry for the late response.
These values while the car is not moving, idle, what happens when you step on the gas or open the throttle? How much should the short and long fule trim be???
what does it mean if both my o2b1s1 and o2b1s2 go to a steady 0.20 (could be 0.020 i forget, but point is it's steady and will have pending code) when the fan or stereo is on? when i turn both off, those sensors seem to fluctuate again.
also, are the o2 sensors supposed to go to steady value like i mentioned in park? all my o2 sensors (2 banks 2 sensors each) drop to a steady 0.20 or 0.40 in park. or is that a function of not being in closed loop like you mentioned, because i didnt let my bank 1 sensors run long enough (because of the stereo or fan being on)?
Thanks for the video.
I ran the OBD on my car, monitored values real time and found that my bank 1 sensor 1 and bank 2, sensor 1 are showing values between 4% and -4%. However, bank 1 sensor 2 and bank 2 sensor 2 are both stuck at 99.22%. Getting P2096 code after I got the shop to install the complete catback solo exhaust. What's your take on this? Can't be the sensors going bad. I am assuming they didnt plug it in properly etc....
I had 2 o2 sensors that gave info that was badly interpretated by the car CPU mpg 13.5 rebooted the CPU Now mpg 19.5.
What's mean CPU buddy 🤔
Good job. Others start with the wheels and after a while get to the fuel.
Hi, so good video! My understanding for videos before is that the sensor 2 downstream is not ok and can also be catalysator
This is a very informative video
I have a 2001 chevy prizm 1.8 toyota vvt , (no i or 4 , different engines). Should the readings be the same where the O2 sensors or air/ fuel sensor and fuel trim readings are concerned? Thanks. J.
Thx so much for making these :)
2001 Toyota Camry 2.2 le , o2 b1s1>>>> 3.25. +/ - 02b1s2>>>>0.050. What is o2b1s1 reading mean ? Your video is very very informative thanks
On a cold start, does the oxygen sensor post cat heater command need to be at 100% or its okay to have a a 10% value ?
Thank you for the information, I have a Toyota corolla LE 2012 and I failed the smog test because of 02 sensor and cat but my car did not show any code also I follow a Toyota drive cycle and I drove 360miles highway 55 t0 60 after I slow down without using break just helping the car with hand break to 35-45 but still not ready! but when I plugged my OBD2 IT SHOW THAT MY O2S1 bank1 (V)=3.306 AND O2S1BANK2 (V)= 0.660 the car was warmed up for more than 10 min ! please do I need to change both 02 and after drive it probably it will make the car ready for emission! thank you very much
Hey. Superb video. I have strange problem with short fuel trims. My engine is BMW M54B30. On bank 1 i got +25-28%, but on bank 2 it is ok 0 to 5%. I know that my oxygen sensor after cat on bank1 is dead. Is this can affect on fuel trims?
MAF is working, I checked rubber hoses and there is no cracks.
Help please. Thanks.
Great video I have a 1997 suburban 454 3out if the 4 o2s are reading 700ish MV and long term fuel both banks is +9 do you think my o2s are bad? ThNk you for any advice...
My 97 tacoma 2.7 is running at +13 long term fuel trim running at highway speeds and my short term fluctuating between + and -. My 02 sensor is hanging at 0.135v. Would those numbers suggest a lean condition pointing towards weak fuel delivery?
Thanks, watched video twice. So understand how its all goes together. ? My shortT reading -17. Longt 0.0 so how I'm understanding my issue is not vacuum leaks. Itd a fuel issue. . so my ? Is I have been putting fuel injector cleaner and its not that. So I'm gonna go with a fuel injector is clogged ? So I would have to basically clean all of them because I don't know what fuel injector is they don't label which one would be the one bad right?
Thank you so much for your help. I so understand how it works. So what would I do next do I put maybe a direct cleaner to the fuel injectors or do I have to clean each one by hand which I don't even know how to do I'm going to touch them before and I'm a female mechanic for 25 yes. You and wiring electrical was not my thing though I so confused with injectors does this but if you could like give me a little push or something what should I look for I mean what should I do for the injectors and if it doesn't clear up see my fuel pump was a new fuel pump was put in like I want to say maybe a year and a half ago. I'm leaning more towards of fuel injector clogged I think thank you again have a great night
Thank you for the video I picked up A lot of knowledge I have a 2006 Audi S4 4.2 and the problem I’ve been having is with the long term fuel trim bank one is usually lower than bank two sometimes bank one goes up to 8 to 9 on positive as bank two stays around eight and then shoots up to 12 my mechanic and I have looked at everything we didn’t fine no leaks through the intake , maf or any of the vacuum lines and then every 6 to 7 days I get P0492 P0171 and P0174 lean codes what do you recommend will be the next thing to check for go to be maybe I have bad O2 sensors or could it be coming from the exhaust I’m so frustrated trying to find the problem of this issue also I get a little rough idle on standstill as well other than that the car runs great on highway and on full speed. Please let me know your input would be very valuable Also forgot to mention 02 oxygen sensor on bank two reads 0.00 doesn’t move
Thank you so very much for your time great video man
Hey I appreciate your video thank you
I use obd2 on my toyota vios 2004. The o2 sensor is one "Percent" not "volt". Please help.. is there nornal percentage for o2 sensor? Thank you.
Hey great video but I got a question that will stump you.2001 mustang v6 305k miles cats went out .I replaced the factory cats with flowmaster universal and made basically a entire pipe and 2 new downstream o2 sensors.but at idle my b1s2 reads .060 on average b2s2 is at the same but will go up and fluctuate a few times and back down to around .060...do you tft think I may just have the wrong or defective o2 sensors .Car runs great no power loss or smoke.front o2 sensors read like they should .hasn't thrown any codes but won't complete catalysts monitor.
2016 Sonata Hybrid 151k miles
Idling in Maint mode after 20 mile drive
Smooth idle
No power loss
No mpg loss
No rotten egg smell
Some lifter noise at slow speed, light accelerator, uphill before gearing down.
P0420
New 02 sensor on Bank1 S1 (cat is in manifold)
Sensor 2 (in front of lower cat) is factory.
Any ideas would be greatly appreciated. 👍
STFT 15.6%
LTFT -32.0
02S12 (V) = .790 V
02S11 (mA) 0 to -.05
STSO2FT1 -1.6%
LGSO2FT1 3.1%
CATTEMP11 (576 Celsius)
CATTEMP12 (400 Celsius)
LAMBDA11 0.998 ish
LAMBDA 0.999 ish
Got negative ten long term fuel trims a touch higher on bank 1...a bit low o2 sensor readings on upstream...Maf reading at about 4.3...2001 nissan sentra gxe with the 1.8...runs pretty good but a little rough on the idle...cleaned throttle body and iac...experimented with the egr...any ideas?
got a 09 qx56 infinity, longft1 -3.9 shortft1 -3.9 longft2 -7.0 shorth ft2 3.1 02B1S1 2.47 02B3S1 2.255 02B3S2 0.080 02B1S2 0.050, getting p 0420 code, change bank1 sensor 2 and MAF sensor, CEL stayed off for a day and back on now. took off exhaust bolts and was told CAT looks fine, any advise.
I have a 2004 liberty 3.7 I got two codes, p0132 and p0152 every thing from the pcm to the connectors is okay, I checked resistance in every cable and all are okay, I changed both o2 upstream sensors oem, and still the same keep steady Reading of 1.270 on both o2 Sensors, down stream sensors Reading are weird also, I got 0.035 on both sides sometimes they go up to 0.700 and sometimes the upstreams start to oscilate but for a few seconds. Do you know what can be causing this?
Greetings, I have a suzuki Kizashi 2.4L S.
The ecu throws check engine light with p0101 code.
The fault code is thrown under 3 conditions:
1. Coasting downhill with zero to minimim accelerator input. (Tps at 19.6 degree, MAF at 10-11g/sec)
2. Cold start after 24+hours in colder environment. Ltft drops down suddenly to -11 to -17% but goes back to 0-3%
3. High rpm idle test. Rpm set at 2.5k, stft increases from +1% to 5% and then returns back to 0%to1%.
Can you suggest a way forward? I also have a bad valve cover gasket
Hi how are things ? I have a 2011 Mazdaspeed 3 2.3L Turbocharged with Rich's issues I have the long term fuel trim at sometimes -16, -19,- 17, as the car warms up it becomes more negative, speeding up the long term fuel trim fuel trims, it goes down to -9.50 or sometimes -10.50 could the problem be a vacuum leak, or air leak after the MAF sensor? the short terms always go 0 -0 sometimes +7 but when accelerating sharply sometimes it jumps to crazy numbers like -17 or sometimes +20 what could be the problem friend? I would like to hear the comment
Vacuum leak
Hey there question, so in the same way learned by doing the work myself cause I couldn't pay someone but I'm lost when it's coming to this 02 to short term trim stuff. I have a shrtftb2s2(%) 99.2 and my longft are at 25. I have replaced my intake gasket and put old but good I believe 02 sensors in and it shows my 02 sensors are working and shrtft are working fine. Where should I go from here? 01 Silverado. Truck runs bad in open loop then better in closed loop but still not like it should. Any help would be great.
even though its years old comment,,,,someone might need it,,,,you have a vaccum leak,,,
In an older car, like a 2000, does the ECU use the downstream sensor for fuel at all? I've heard differing opinions, but most people say the secondary O2 sensor after the cat is just there to determine the health of the cat, and only the primary O2 sensor decides the fuel. I put an 02 sensor spacer in mine to get rid of the P0420 and am wondering if that's messing with my fuel trims at all.
That second o2 sensor is there for correcting air fuel ratio, not health of your cat. Some people put the spacer in to trick the ecm when a bad cat is present. It may very well be your issue.
What if you drive a Ford and no O2 sensor voltage can be displayed? My bi directional tool can only display microamps on the downstream sensor, which is meaningless to me. I CAN see voltage on my GM and Chrysler vehicles. Does Ford use a different data point at the ECU to adjust fueling?
Hello I have a 07 g35x and my long term ban 2 is staying at 35.2 everything else is fine do can you tell me why that’s happening is it a oxygen sensor and how do I figure out which sensor it is I’m also get a code p0174 I’d appreciate your help
Hi, I hope you’re still checking your channel. I have a question on data stream codes. What does it mean when my oxygen sensor codes give me N/A instead of a number. (O2B1S1 N/A) I have a reading for B1S2 but then not B2S1, B2S2, B3S2, B4S1 (all have N/A). BTW thank you for these videos. Could you do more on all these other codes? SPARKADV, MAF, etc
02 connections?
How do the first 2 Pids here help in diagnostics, I've been told to ignore them, especially if they are at 99%.
I have a scanner reading on the sensor called Lambda Correction, and it shows a value between 3.5 and 5.0. Is this the same as STFT?
Hello,thank you for the information.
I was wondering if you could help me in the right direction?
I have an 06 5.7 hemi and I'm getting these codes for Lean fuel mix and I've looked it over and I simply can't find a leak anywhere,it does have an aftermarket intake but I'm not sure if that would be the cause.
The Ltft is reading 32% and 21% at idle but they get close to 7% when I'm about 1/3 on the throttle and they return to the previous.
I would appreciate your help.
Thanks
9.4 fuel trim is a bit high.. 😅
I won't even tell you what mine was then lol
I haven't got to figure out my p0171 lean code yet but I think it was because I didn't have an air filter on my cold air because it fit different on my 98 cobra, or i need to plumb the valve cover vent back into the crankcase for positive vacuum because the 98 was a little different that the 01 cobra but it was dumping about 25% on the trim.
Luckily im still breaking in the motor so there was no getting in it with those trim levels.
I’m getting a positive ltft reading only on bank 2 I’ve checked and changed almost everything including catalyst converter and still no change sprayed brake clean around the intake as well
Great info. Thank you. But one observation if you don't mind. 10:25 Isn't spraying "soapy water" on the intake leak sucking it into the engine? I'm no mechanic, but I think that's bad.
Propane
Just subscribed. Would be nice to see examples of what your explaining.
BANK 2 for me is ~50% STFT! and high LTFT also. I used a smoke machine and found a few intake air vacuum leaks.... but still remained. I used the smoke machine into the TAILPIPE and found a badly leaking exhaust DONUT from the exhaust manifold. $5 fix... will find out tmrw hopefully!
Hi, I'm having an issue with my car idling kinda rough and hesitating especially when pulling away from a stop. I'm kinda new to using live data I just wondered if you have any suggestions what I should be looking for? thanks, cars not throwing any codes so I'm kinda struggling with where to start.
Start with easy stuff. Spark plugs, and ignition coils, vacuum leaks, maf sensor. These are typically the cause
Fuel trims somtimes are not accurate, caused by one the sensors, like mine the MAP sensor cause both fuel trim to be at 12 to 14 percent, i tought i have vacuum leak, but it was the aftemarket delphi MAP senosr reporting wrong values to the ECM, i just put back the OEM sensor and the fuel trim went down to 5 percent. I couldnt believe it, the initiale issue was rought idling and somtimes engine misfire, but it was the ignition electric connection wires were loose at the aftermarket start button system, basically i create the problem overtime by using bad quickdisconnect connector, i replace the connector and problem solved partially rought idle and misfire, but fuel trim problem got fixed by installing OEM MAP sensor back.
Any ideas as to why at idle, MAF at times goes below 2.0 g/s and Oxygen Sensor Current (B1-S1) goes into the negative? I have 3rd GEN MINI COOPER S