I agree. The cat could be plugged But I’d be checking those replacement coils on those cylinders aftermarket crap. Seen to many crap out under load. Looking forward to your find!!
Might want to make sure the gaps are right. Just looking at the plugs should tell you what is working. What bad parts can cause rich running? Listed in #2 video.
I watch this channel to learn more about how to keep my 21 year old van on the road, but the big bonus in this channel is getting to see scenes from my much beloved and missed home state. Thanks for that. It made my day.
Ivan, you are amazing. As meticulous as you are, I hope you produce a digital record of your findings for purchase. This would be a very valuable tool for every mechanic in the country, world.
Im bettin its melted cats I would not count out a bad upstream o2 on bank 1 either..Running rich like that and burning all the loaded fuel built up is not good on cats. Im only a few months in on learning all this stuff thoo. I dont know if there is a down stream cat plugged and contaminating bank 2 or is that even possible? I just finished chapter one of danners classes. There is a lot to this stuff to learn. I learned a little the day you were here thoo. Thanks Ivan.
Do any of these people who get ripped off by shop's who just throw parts, and don't diagnose the problem ever get their money back??? I fix all my own vehicle's, because I don't trust anyone to do an oil change right. My dad passed away last year, and I ended up with his truck. I went to do an oil change, and they were to lazy to put the right filter on, and put a smaller filter on. I have an 05 ranger with the 3.0, and the filter isn't that easy to get to, and it has this funnel to keep the oil from dripping onto the starter. The truck had left a leak spot only after driving, so i figured it was the filter, which was not even close to hand tight. I had a guy flag me down from an oil change place, and he showed me his dipstick that had no oil on it, and he was protesting the guy because the drain plug fell out, and locked his motor up, and he had it towed to the lube shop to make them take care of it, but they had already closed for the day. The guy went down the road with his phone, recording all the oil leaking it did. I have known two other people with the plug falling out. Part cannon city, along with junk parts from china, and then your car is still broke, crazy. Thanks for all the great content. God bless.
What are the odds that all the after market parts are working? Bought the headlamp from your store as a little thank you gift for some friends and all are appreciative. Stay well
A buddy of mine asked my advice for 1 side running rich, his opinion was o2 sensors, I said no, it's something else. The data and the smell said rich. Ended up being a leaking pressure regulator
That was my first hunch. Short term fuel trims were at -15% but the car smelling of gas? That would mean leaky injectors or something wrong upstream. It could also be a fuel rail overpressure leading to the fuel flow being completely wrong. If it was a plugged exhaust that caused the sensors to go rich, it would mean the sensors read high but the car would not smell of gas.
Quite an interesting case study Ivan!, can't wait to see the next part/s of the diagnosis. Throwing parts at the vehicle indeed throws off the diagnosis and starting from scratch is really the way to go. My bet is on a clogged portion of the exhaust system.. Cheers!
I would say less about the diagnostic mindset and more about an in depth understanding of how the systems work beyond "suck squeeze bang blow". Not that one is more important than the other, but it seems to be (more often than not) a lack of understanding of pretty rudimentary principles. This is definitely an interesting one though. @Pine Hollow Auto Diagnostics, what's the bet it's not one of the options you listed and turns out to be some weirdo problem with the intake manifold? ;)
Hey Ivan. The O2 sensors were reading lower than bias (except for one I think I saw) because the heaters turn on KOEO which drops the voltage. It is a test that you can use to check for heater operation.
I used to work at a used car yard, higher cylinder pressures require higher ignition voltage to jump the spark plug gap, which a fowled plug would undermine. Change the plugs. If you load the engine just below the point of misfiring, you can get the plugs to clean themselves up sometimes A blocked cat subdues the exhaust note, the exhaust note sounded pretty throaty in the garage
This higher ignition voltage required on high cylinder pressure might also cause the spark to jump somewhere outside the cylinder. I would test the coils and spark plug leads using Ivan's proven method of pointing a test light at it.,
Many times I was the last tech that they called .there is nothing quite like following a string of parts changers . Diagnosis by replacement pays well one time but leaves a bad taste in the customers mouth .
I would bet on the cats .all these aftermarket makers are reproducing these parts cheap as they can. I'm a firm believer in OEM parts if the budget can afford
Thing is it's running rich AF, so while the cat may have been fine when it was put in... It could have been trashed by now with all the fuel being poured into it. Think about it, how would a muffler only be causing trouble on bank 1? Bank 1's cat however...
I’m HOOKED!!. Need more Why Ivan Why… Didn’t like the MAF reading at first was way to high in the beginning for a 5.3L but came down I guess as it warmed up I think the other shops fixed the problem or was on the right track for fixing but using cheapo Mexico parts made it worst GM TECH OUT
Those motors are a pain to diagnose… the few I’ve had to mess with had about a dozen small issues, lots of vacuum leaks and on and on and on… never ending…
Hi Pine Hollow. 97 grand voyager 3.3 crank, no start, no spark. Fuel pressure perfect. All fuses good. Replaced cam and crank sensors. Then noticed ASD relay has no power on the circuit when key on engine off.
Instead of a possible plugged cat, I wonder if there was cast flashing in those brand new looking headers that could be plugging up the Exhaust??? Looking forward to part 2 Ivan!!!!!
I diagnosed my car and came to the conclusion it was the exam. I told my wife to get napa to change ecm and program it. They told her they needed to diagnose themselves and it ended up costing double. It was ecm like I thought.
in the older days of TBI injection setups, the computers very often went south, and many times due to bad injector/s cooking the drivers. ( pre-obd2). of course then you went to any junkyard, pulled one from similar car/matching main ECM number and just swapped the chips over to transfer the correct calibration over. showing my age again I guess 🤪
I would say you have several issues going on. Just the fact that the one O2 sensor is almost touching the frame tells me that it's the wrong one or definitely aftermarket if the exhaust pipe is original and in the original position. With the misfiring and the rich condition, the new cats could already be bad depending on how long it's been driven with those symptoms going on after the cat replacement. I can't wait to see part 2.
Its worth fixing these old trucks because they last forever unlike these newer ones that barely make it thru the warranty period. I love CHEVY and GMC trucks and vans.
Are those spark plugs actual AC Delco/GM, and are they the correct ones? Being a former GM dealer mechanic, I replaced many many wrong plugs for engine running issues. Precision Tune and Firestone were notorious for installing wrong plug types. That 5.3 had like 5 revisions on the plugs.
No just GM, I've had it happen on Dodge and Mitsubishi. Chasing a misfire for days, because I replaced the plugs. (Can't be the plugs, I thought. THEY'RE NEW) Sure enough, quality brand plugs were the problem both times.
Hey Ivan, it's been a while, but I seem to remember that this year had two different up stream sensors. One was Delphi and I think the other was Denso(?) Not sure. I never had both in hand but if the sensor you showed is too long (touching the frame) it could be the wrong one. Also, the ground for those sensors is one of the upper bell housing bolts. We have had a couple of these in my classroom that my students diagnosed O2 issues on over the years.
Unfortunately "Getting money back" from a slew of blunders is worse than dealing with your insurance company after a accident. Especially now adays considering the world we live in
Why aren’t O2 sensors switching when in closed loop? Does the truck never go to closed loop? That exhaust is suspect too, especially mashing the O2 sensor wires against the frame.
HI IVAN ,looks like another great video.The videos lately have been great,all these people with so many different problems that have been looked at by many many mechanics.i think a small part of the issue is if they had them at the dealer or a high volume repair shop the pressure on rookie mechanics to fix or find something wrong so they can bill hours to the job is just to big.So they SHOOT THE PARTS CANON,in this case it's more like a gatilling gun.AND then send it,saying if it screws up bring it back.It also could be that they GOT the right part,that was the issue but USED A LOW QUALITY replacement that didn't meet the specs THE CAR Needed to run well.You are #1 as far as I'm concerned on TEACHING how to diagnose an issue and confirm that the part is the CORRECT part, once the repair is done.I hope you consider a TEACHING career once you get TIRED of actual repair.your knowledge and ability to diagnose should be passed down to STUDENTS.So thanks
Since I dont have a pressure transducer, my next step would be to move the plugs and see if fouling followed them before I declared them to not be fouling as, I would want to rule them out completely as participating in the issues. As you describe the problem I am leaning to the notion that a rich mixture has crapped the aftermarket cats especially the right side, however you have not really explained how many miles or hours this truck might have been driving. lacking a transducer, and assuming there is no crossover I would look for a spot in the cam where all exhaust valves on bank 1 are closed and i would dump 100 PSI of compressed air into the Bank 1 pipe at the sensor hole and I would measure pressure using a screw in gauge at the back sensor hole. If there is a crossover, a simple sawzall cut followed by inserting a hunk of 18 ga sheetmetal would separate the two sides. If this "test" revealed no sever lag in delivering pressure through thc cat, I would move on to looking at the remainder of the exhaust. In the end I think you are going to return to that sensor that was touching the frame to solve your sensor voltage issue? .
Would be interesting to know how much that customer had to pay up till now and how this all started out. Was it something that all of a sudden happened etc ... .
Right off the bat I believe we have upstream o2 sensor issues. Ive never seen them flatline that long. Usually they will start cycling up and down .2v up to .8v ..
You may want to be careful with the music that you have playing in the background (I.e. the radio in the car). RUclips has been pretty efficient at spotting copyrighted music and demonetizing (as well as muting audio). On another note, I find your videos very interesting, thanks for taking along.
This issue sounds alot like when Bank 1 Sensor 1 wire was shorted on our 6.0L, something chewed the wires. It caused the computer to go crazy, misfires and few other issues. I wonder if the O2 sensors and the coils share common source within the ECM.
Ivan, I'm 5 minutes in.....i wondered if the timing chain was replaced? That can throw a misfire with the timing off. I checked the fuel trims and found that the timing was way off, tore into the engine, found that the chain was so much slop in it. Replaced the chain with new sprockets and oil pump. The engine runs so perfectly! Glad i found that problem. It's now 318,000 miles, haha. I'll gonna finish watching it now.
@@PineHollowAutoDiagnostics thank you. I am SUPER shade tree and love your content. I only wish you were closer. In another comment, I said I have lost confidence in local mechanics after watching you and Eric. Thanks so much!
@@PayNoTax-GetNoVote very true. But it did happen in my case plus i was getting p0300 as well. Random misfire, not just 1 or 2, that's when i knew the chain was worn out
Good video ! I would go for one area at a time exhaust then fuel then ignition that way you can eliminate possibly of bad aftermarket parts . I am taking a stab at first bad aftermart part or parts then a crack intake manifold
In my great uncles stepdaughters Ford EL Falcon it had a problem with the ground wire causing that sort of problem because the fuel injectors & the ignition coil is grounded through the wire which had a corrosion problem,it wasn't firing properly on cylinder number 6 & the spark plug was a bit wet. It's possible that the PCM in the car in the video has a short circuit or a partial short circuit in the ignition coil signal circuit or fuel injector driver circuit,a possible cause is water inside the PCM,I have had that problem before. It could be something a simple as a corroded terminal in a wiring connector or in the PCMs wiring harness or the wiring harness could be chafing on the chassis ground somewhere therefore causing it to short to ground, check the loom visually to see if it has been melted through by the exhaust headers, etc,I've had to do some wiring loom work on a 1991 model Toyota SV21 .Camry which had an overheated but not seized engine in it,some of the wires melted.together & shorted out inside of the loom. If it runs a return style of fuel system then there may be a blockage in the return side of the fuel system, it's a possibility that could be causing the "pig" rich condition as well
This a good one. I would like to see the coil power, ground and signal on the scope. If I had to guess, I would say a PCM ground issue. You'll find it.
My Silverado was doing the same thing! Turned out to be loose grounds! So I re-grounded and sealed every bolted ground connection. Fixed Originally I thought it was odd that the problem seem to clear up when the truck would get wet or drive in the rain! Bingo. Now its rock solid. There’s a list of ground connections to check on a Silverado.
I had this exact issue on a 5.3 After fuel pump replacement. Customer replaced the fuel pump at another shop and got hosed for 600 bucks. The fuel pump was replaced because they believe that the fuel tank was sabotaged. Then they replaced the spark plugs with champion plugs for a lawnmower. Once I emptied and cleaned tank and then put a good set of ac delcos in and a tank of 104 octane in it literally came to life. Guy said it put pepper in his stepper what I’d done to it. Then he got tboned 2 weeks later so no clue if it lasted.
Why is LTFT -1.56% and STFT only ca. -10% on both banks? Also, spraying brake cleaner around the intake manifold on the affected bank changed the fuel trims despite there being no leaks per a smoke test. There are surely two distinct problems. What done it?
Wow what does this say about the diagnostic skill of our current technicians ‼️ Is this a problem at the dealer level too. Are cars becoming too complicated to keep up with ? I started in 1972. We didn’t really understand the new EGR systems that were just starting to show up until up in the 80’s. I enjoy your videos because I enjoy the challenge. I’m retired 5 years after 45 years and can already see I’m falling behind the technology. Looking forward to the answer. We used to tell those parts cannon owners to take all those parts back and then they could afford to pay us to diagnose their problem.
Look for tracking or cracks then change all the plugs & boots as necessary . Plugs are consumables & almost cost nothing . A damaged cat is possible if its run like this for some time ( $$$$$ OUCH ! ) . What we're learning is always keep the old parts when firing the cannon ! PS I always keep 2 used spark plugs in the car , a headlight bulb , a mix of fuses & a 2L bottle of dihydrogen monoxide , hydroxylic acid or DHMO Just go with the lowest cost versions you can find but stay away from the foreign stuff .
Wow, so many shops had a stab at it lol. (I think they need to do a course on engine management logic). Who could supply that 😀. So in open loop mode the computer is using default settings that are close enough to allow it to run?. The second it has sensors, logic hell breaks loose lol, plus any vaccume leaks/breaches could confuse matters.
Strong smell of gas suggests that O2 sensors are not incorrect/defective and exhaust really is that rich. Cat on Bank 1 could be compromised as a result. So that may need to be replaced, depending on results of pressure testing. But why is exhaust rich? Insufficient spark? Test those aftermarket ignition coils. Looking forward to part 2.
Watched first 9 minutes, my first educated guess would be stuck open Evap Purge Valve ? Fuel droplet's and vapors steady drawing into the intake manifold....
Omg!! I live in Ithaca! Next time you’re here, would love to take you to lunch!! You’re work is awesome!
I agree. The cat could be plugged
But I’d be checking those replacement coils on those cylinders aftermarket crap.
Seen to many crap out under load.
Looking forward to your find!!
Might want to make sure the gaps are right. Just looking at the plugs should tell you what is working. What bad parts can cause rich running? Listed in #2 video.
i admire the mindset of IVAN
and when i am troubleshooting
i get my extra energy from him
I watch this channel to learn more about how to keep my 21 year old van on the road, but the big bonus in this channel is getting to see scenes from my much beloved and missed home state. Thanks for that. It made my day.
parts cannon, sounds more like a 155 mm parts howitzer LoL. another excellent video thanks Ivan !
It reminds me the 8 inch howitzer
Yeah - one of those 155's the yanks had in Germany to lob nuclear tipped artillery shells into the Fulda gap. 😆
More like a parts A-Bomb.
Yes, a Parts Howitzer. Well posted!
I love Johnny Hates Jazz - shattered dreams! Great case study anxious for part 2
What ever you charge for your service is likely not enough. Love the channel!
Too bad the original parts are long gone. I'd put the old "crap" back and start over again.
I repaired a NY Corvette many years ago with similar symptoms, by cleaning the corrosion off the ECM connector.
Ahhhh! You making my gears turn. Had a Suburban like that. I love me some Stabilant 22. Have a tube I bought close to 10 year ago. Stuff works.
Amazon says: Last purchased Oct 11, 2015.
I love your "new" multi-part shows!
I watch your videos all the time and I love them . I find it all so fascinating and I've learned a lot . Thank you !
Ivan, you are amazing. As meticulous as you are, I hope you produce a digital record of your findings for purchase. This would be a very valuable tool for every mechanic in the country, world.
Im bettin its melted cats I would not count out a bad upstream o2 on bank 1 either..Running rich like that and burning all the loaded fuel built up is not good on cats. Im only a few months in on learning all this stuff thoo. I dont know if there is a down stream cat plugged and contaminating bank 2 or is that even possible? I just finished chapter one of danners classes. There is a lot to this stuff to learn. I learned a little the day you were here thoo. Thanks Ivan.
Do any of these people who get ripped off by shop's who just throw parts, and don't diagnose the problem ever get their money back??? I fix all my own vehicle's, because I don't trust anyone to do an oil change right. My dad passed away last year, and I ended up with his truck. I went to do an oil change, and they were to lazy to put the right filter on, and put a smaller filter on. I have an 05 ranger with the 3.0, and the filter isn't that easy to get to, and it has this funnel to keep the oil from dripping onto the starter. The truck had left a leak spot only after driving, so i figured it was the filter, which was not even close to hand tight. I had a guy flag me down from an oil change place, and he showed me his dipstick that had no oil on it, and he was protesting the guy because the drain plug fell out, and locked his motor up, and he had it towed to the lube shop to make them take care of it, but they had already closed for the day. The guy went down the road with his phone, recording all the oil leaking it did. I have known two other people with the plug falling out. Part cannon city, along with junk parts from china, and then your car is still broke, crazy. Thanks for all the great content. God bless.
Watching Ivan this afternoon, this is the Fifth Chevy truck in a row. No wonder Eric O loves them.lolol.
What are the odds that all the after market parts are working?
Bought the headlamp from your store as a little thank you gift for some friends and all are appreciative. Stay well
Yep. I've had brand new spark plugs not work. Chased a misfire for days because I ruled out a new part.
Great study! Cant wait for Part 2!
I had one with similar symptoms that had a leaking fuel pressure regulator.
A buddy of mine asked my advice for 1 side running rich, his opinion was o2 sensors, I said no, it's something else. The data and the smell said rich. Ended up being a leaking pressure regulator
That was my first hunch. Short term fuel trims were at -15% but the car smelling of gas? That would mean leaky injectors or something wrong upstream. It could also be a fuel rail overpressure leading to the fuel flow being completely wrong.
If it was a plugged exhaust that caused the sensors to go rich, it would mean the sensors read high but the car would not smell of gas.
I had the fuel pressure regulator on my list of things to check as well, especially with a hard start.
Quite an interesting case study Ivan!, can't wait to see the next part/s of the diagnosis. Throwing parts at the vehicle indeed throws off the diagnosis and starting from scratch is really the way to go. My bet is on a clogged portion of the exhaust system.. Cheers!
after the fact
Ivan, looks like you've found another one. Can't wait to see how this turns out. Thanks for Sharing!
waiting for part 2 Ivan! Have a Happy New Year!
Your videos have better cliffhangers than most drama programmes.
xD
What a joke, 7 shops. man we need to get this auto industry together.
Love that Cowboys towel. Ivan will find and fix that problem, no doubt
It's like house, but for cars. Magnificent!
The difference between a technician vs a mechanic is the parts cannon vs diagnostic tools and diagnostic mindset.
I would say less about the diagnostic mindset and more about an in depth understanding of how the systems work beyond "suck squeeze bang blow".
Not that one is more important than the other, but it seems to be (more often than not) a lack of understanding of pretty rudimentary principles.
This is definitely an interesting one though.
@Pine Hollow Auto Diagnostics, what's the bet it's not one of the options you listed and turns out to be some weirdo problem with the intake manifold? ;)
Hey Ivan. The O2 sensors were reading lower than bias (except for one I think I saw) because the heaters turn on KOEO which drops the voltage. It is a test that you can use to check for heater operation.
Yes excellent point! On this older model the heaters are not computer-controlled, so they are always on with the key on :)
Detective Ivan is on the scene I have a feeling you will find the culprit(s). Thanks Ivan and have a Happy New Year.
Great vids Ivan. Have a happy New Year.
I used to work at a used car yard, higher cylinder pressures require higher ignition voltage to jump the spark plug gap, which a fowled plug would undermine. Change the plugs.
If you load the engine just below the point of misfiring, you can get the plugs to clean themselves up sometimes
A blocked cat subdues the exhaust note, the exhaust note sounded pretty throaty in the garage
This higher ignition voltage required on high cylinder pressure might also cause the spark to jump somewhere outside the cylinder. I would test the coils and spark plug leads using Ivan's proven method of pointing a test light at it.,
Or shoot some water in the intake steam clean.
Ivan building up the hype on this case
Many times I was the last tech that they called .there is nothing quite like following a string of parts changers . Diagnosis by replacement pays well one time but leaves a bad taste in the customers mouth .
your skills amazes me as you have big headaches that you work through patiently!!
I wouldn't bet on a new cat being restricted, but a muffler restriction may have been overlooked. Good to get back pressure out of the way though.
Muffler restriction(unless it's a true dual exhaust) would show on both banks.
I've had cats that were one-way flow,installed backwards,that did this.
I would bet on the cats .all these aftermarket makers are reproducing these parts cheap as they can. I'm a firm believer in OEM parts if the budget can afford
Exhaust restriction would show as a high upstream EGT.
@@Stoney3K Unfortunately EGT isn't something that's monitored by the engine management on these vehicles.
Thing is it's running rich AF, so while the cat may have been fine when it was put in... It could have been trashed by now with all the fuel being poured into it. Think about it, how would a muffler only be causing trouble on bank 1? Bank 1's cat however...
Thank you Iven I was wondering why when I revved the engine to 6500 the missfire cleared up
Can't wait for part 2 to find out the issue.
I’m HOOKED!!. Need more Why Ivan Why…
Didn’t like the MAF reading at first was way to high in the beginning for a 5.3L but came down I guess as it warmed up
I think the other shops fixed the problem or was on the right track for fixing but using cheapo Mexico parts made it worst
GM TECH OUT
I think someone left the choke on.
Exactly what I started to say. Great minds think alike.
yep, cold weather coming, gotta clean, lube and adjust that choke and linkage.
That was great...I went to comment on the comment.....and then I see Watch Wes Work's handwriting.
Wes be nice😐
@@abilioarruda4619 ......it could happen.....
Those motors are a pain to diagnose… the few I’ve had to mess with had about a dozen small issues, lots of vacuum leaks and on and on and on… never ending…
Actually quite simple compared to the newer GDI VVT TURBO junk 😁
Ivan, always good stuff, thanks, but see that Cowboys blanket behind you? Get rid of that thing! That's the problem!! lol 😎 HNY
Aftermarket O2 sensors
Listen to that piston slap😂😂 Raaaa.....Raaaaaa
Hi Pine Hollow. 97 grand voyager 3.3 crank, no start, no spark. Fuel pressure perfect. All fuses good. Replaced cam and crank sensors. Then noticed ASD relay has no power on the circuit when key on engine off.
Instead of a possible plugged cat,
I wonder if there was cast flashing
in those brand new looking headers
that could be plugging up the
Exhaust??? Looking forward to part 2 Ivan!!!!!
I can't believe they have not replaced the ECM yet. Usually, people have put several on those on at this stage. 🤣🤣
I diagnosed my car and came to the conclusion it was the exam. I told my wife to get napa to change ecm and program it. They told her they needed to diagnose themselves and it ended up costing double. It was ecm like I thought.
@@mordosamsonite5833 I've been told ECM's seldom go bad. I just replaced mine.
in the older days of TBI injection setups, the computers very often went south, and many times due to bad injector/s cooking the drivers. ( pre-obd2).
of course then you went to any junkyard, pulled one from similar car/matching main ECM number and just swapped the chips over to transfer the correct calibration over.
showing my age again I guess 🤪
Sitting here thinking selfishly, I wish he was my neighbor
Your approach to every single car is absolutely awesome.
Thanks 👍 for sharing your knowledge us
Part 2 bring it on!!!
Are all your customers called Don?😜 The golf cart guy was called Don too I think 😂
Haha two Dons in a row!
How could you leave us like that? I can't stand the suspense!
I would say you have several issues going on. Just the fact that the one O2 sensor is almost touching the frame tells me that it's the wrong one or definitely aftermarket if the exhaust pipe is original and in the original position. With the misfiring and the rich condition, the new cats could already be bad depending on how long it's been driven with those symptoms going on after the cat replacement. I can't wait to see part 2.
Its worth fixing these old trucks because they last forever unlike these newer ones that barely make it thru the warranty period. I love CHEVY and GMC trucks and vans.
you bet I still drive my 1991 GMC 1500
Its worth fixing old trucks solely due to the expense of new trucks. New truck dollars will purchase bulk ammo for the parts cannon.
when it comes to Computer diagnostics you and Scanner Danner at Rosedale are my go to guys.
Are those spark plugs actual AC Delco/GM, and are they the correct ones? Being a former GM dealer mechanic, I replaced many many wrong plugs for engine running issues. Precision Tune and Firestone were notorious for installing wrong plug types. That 5.3 had like 5 revisions on the plugs.
id a gm mechanic who demanded the correct plugs....
No just GM, I've had it happen on Dodge and Mitsubishi. Chasing a misfire for days, because I replaced the plugs. (Can't be the plugs, I thought. THEY'RE NEW)
Sure enough, quality brand plugs were the problem both times.
O2 sensors are wrong....+ coil packs on the missfire counter
Intake manifold leak would cause functioning sensor to increase flow to injector to avoid lean condition?
The suspense is killing me
Have a 4.8 2000 silverado doing the same type thing. So looking forward for clues. Haven’t parts cannonball it yet😅
Looking forward to part 2 !
I'm really waiting for part two .. it's almost like a soap opera lol I'm going with a crook cat ..
When the parts cannon doesn't fix it, the diagnostic mindset will.
inlet temp and outlet temp to the catylitic converter.halfway thru the vid i'd check if that cat is gettting red hot or not???
Hey Ivan, it's been a while, but I seem to remember that this year had two different up stream sensors. One was Delphi and I think the other was Denso(?) Not sure. I never had both in hand but if the sensor you showed is too long (touching the frame) it could be the wrong one. Also, the ground for those sensors is one of the upper bell housing bolts. We have had a couple of these in my classroom that my students diagnosed O2 issues on over the years.
Unfortunately "Getting money back" from a slew of blunders is worse than dealing with your insurance company after a accident.
Especially now adays considering the world we live in
Another interesting issue! Ivan, I can't wait to see if your gut feeling is correct. Thanks for posting it.
Why aren’t O2 sensors switching when in closed loop? Does the truck never go to closed loop? That exhaust is suspect too, especially mashing the O2 sensor wires against the frame.
What about the bad ground, do we know where that is and about any related sensor circuits connected to it?
And, like Heinz ketchup, anticipation is making me wait.
HI IVAN ,looks like another great video.The videos lately have been great,all these people with so many different problems that have been looked at by many many mechanics.i think a small part of the issue is if they had them at the dealer or a high volume repair shop the pressure on rookie mechanics to fix or find something wrong so they can bill hours to the job is just to big.So they SHOOT THE PARTS CANON,in this case it's more like a gatilling gun.AND then send it,saying if it screws up bring it back.It also could be that they GOT the right part,that was the issue but USED A LOW QUALITY replacement that didn't meet the specs THE CAR Needed to run well.You are #1 as far as I'm concerned on TEACHING how to diagnose an issue and confirm that the part is the CORRECT part, once the repair is done.I hope you consider a TEACHING career once you get TIRED of actual repair.your knowledge and ability to diagnose should be passed down to STUDENTS.So thanks
Thank you so much for the feedback, Roberto! Glad you are finding value in the video case studies :)
Since I dont have a pressure transducer, my next step would be to move the plugs and see if fouling followed them before I declared them to not be fouling as, I would want to rule them out completely as participating in the issues. As you describe the problem I am leaning to the notion that a rich mixture has crapped the aftermarket cats especially the right side, however you have not really explained how many miles or hours this truck might have been driving. lacking a transducer, and assuming there is no crossover I would look for a spot in the cam where all exhaust valves on bank 1 are closed and i would dump 100 PSI of compressed air into the Bank 1 pipe at the sensor hole and I would measure pressure using a screw in gauge at the back sensor hole. If there is a crossover, a simple sawzall cut followed by inserting a hunk of 18 ga sheetmetal would separate the two sides. If this "test" revealed no sever lag in delivering pressure through thc cat, I would move on to looking at the remainder of the exhaust. In the end I think you are going to return to that sensor that was touching the frame to solve your sensor voltage issue?
.
Would be interesting to know how much that customer had to pay up till now and how this all started out. Was it something that all of a sudden happened etc ... .
It was over a year.
O2 sensors wiring I 'd also check secondary ignition
Right off the bat I believe we have upstream o2 sensor issues. Ive never seen them flatline that long. Usually they will start cycling up and down .2v up to .8v ..
You may want to be careful with the music that you have playing in the background (I.e. the radio in the car). RUclips has been pretty efficient at spotting copyrighted music and demonetizing (as well as muting audio). On another note, I find your videos very interesting, thanks for taking along.
Thanks Ivan, absolutely a great case study!
This issue sounds alot like when Bank 1 Sensor 1 wire was shorted on our 6.0L, something chewed the wires. It caused the computer to go crazy, misfires and few other issues. I wonder if the O2 sensors and the coils share common source within the ECM.
Common source might not be a good idea in design. In other words separate ground wires.
Ivan, I'm 5 minutes in.....i wondered if the timing chain was replaced? That can throw a misfire with the timing off. I checked the fuel trims and found that the timing was way off, tore into the engine, found that the chain was so much slop in it. Replaced the chain with new sprockets and oil pump. The engine runs so perfectly! Glad i found that problem. It's now 318,000 miles, haha. I'll gonna finish watching it now.
I'd say plugged cat though. Or fouled spark plugs....
Why would a timing chain issue only be on one bank?
@@PayNoTax-GetNoVote That is the LOGICAL question on a single-cam engine :)
@@PineHollowAutoDiagnostics thank you. I am SUPER shade tree and love your content. I only wish you were closer. In another comment, I said I have lost confidence in local mechanics after watching you and Eric. Thanks so much!
@@PayNoTax-GetNoVote very true. But it did happen in my case plus i was getting p0300 as well. Random misfire, not just 1 or 2, that's when i knew the chain was worn out
Good video ! I would go for one area at a time exhaust then fuel then ignition that way you can eliminate possibly of bad aftermarket parts . I am taking a stab at first bad aftermart part or parts then a crack intake manifold
Great video 👍
I'm going with bad O2 sensors. It looks like they are hitting the frame, which has possibly worn through the wiring harness coming out of the sensors
In my great uncles stepdaughters Ford EL Falcon it had a problem with the ground wire causing that sort of problem because the fuel injectors & the ignition coil is grounded through the wire which had a corrosion problem,it wasn't firing properly on cylinder number 6 & the spark plug was a bit wet.
It's possible that the PCM in the car in the video has a short circuit or a partial short circuit in the ignition coil signal circuit or fuel injector driver circuit,a possible cause is water inside the PCM,I have had that problem before.
It could be something a simple as a corroded terminal in a wiring connector or in the PCMs wiring harness or the wiring harness could be chafing on the chassis ground somewhere therefore causing it to short to ground, check the loom visually to see if it has been melted through by the exhaust headers, etc,I've had to do some wiring loom work on a 1991 model Toyota SV21 .Camry which had an overheated but not seized engine in it,some of the wires melted.together & shorted out inside of the loom.
If it runs a return style of fuel system then there may be a blockage in the return side of the fuel system, it's a possibility that could be causing the "pig" rich condition as well
In Arkansas that's like one of the most common trucks around and none of them have catalyst converter's
Very interesting. Thanks Ivan!
This a good one. I would like to see the coil power, ground and signal on the scope. If I had to guess, I would say a PCM ground issue. You'll find it.
I think they loaded up the blunderbuss with all the parts they could find and shot it.
DAS BLIETZKRIEG!!
My money is on one original problem compounded by at least one new problem introduced by the parts cannon.
Scanners help so much
My Silverado was doing the same thing! Turned out to be loose grounds! So I re-grounded and sealed every bolted ground connection. Fixed Originally I thought it was odd that the problem seem to clear up when the truck would get wet or drive in the rain! Bingo. Now its rock solid. There’s a list of ground connections to check on a Silverado.
I had this exact issue on a 5.3
After fuel pump replacement. Customer replaced the fuel pump at another shop and got hosed for 600 bucks.
The fuel pump was replaced because they believe that the fuel tank was sabotaged.
Then they replaced the spark plugs with champion plugs for a lawnmower. Once I emptied and cleaned tank and then put a good set of ac delcos in and a tank of 104 octane in it literally came to life. Guy said it put pepper in his stepper what I’d done to it. Then he got tboned 2 weeks later so no clue if it lasted.
Why is LTFT -1.56% and STFT only ca. -10% on both banks? Also, spraying brake cleaner around the intake manifold on the affected bank changed the fuel trims despite there being no leaks per a smoke test. There are surely two distinct problems. What done it?
Wow what does this say about the diagnostic skill of our current technicians ‼️ Is this a problem at the dealer level too. Are cars becoming too complicated to keep up with ?
I started in 1972. We didn’t really understand the new EGR systems that were just starting to show up until up in the 80’s.
I enjoy your videos because I enjoy the challenge. I’m retired 5 years after 45 years and can already see I’m falling behind the technology.
Looking forward to the answer. We used to tell those parts cannon owners to take all those parts back and then they could afford to pay us to diagnose their problem.
But it was not the owner, seven shops, remember? So I'm 78 and still have to fix my own cars, still looking for a good mech.😁
Dang, you left us hanging!
After market Cats might be the problem in this case there not the best should have oem parts when it comes to exaust parts for sure....
@ 3:50 Sounds like more investigation into the leak issue is in order imo
hows the fuel pressure? i had a one of those at 100psi at idle. too high, fuel pump was bad
Why is there never any ice cream in Ivan’s videos? This was definitely a double cone triple scooper.
Look for tracking or cracks then change all the plugs & boots as necessary .
Plugs are consumables & almost cost nothing .
A damaged cat is possible if its run like this for some time
( $$$$$ OUCH ! ) .
What we're learning is always keep the old parts when firing the cannon !
PS
I always keep 2 used spark plugs in the car , a headlight bulb , a mix of fuses & a 2L bottle of dihydrogen monoxide , hydroxylic acid or DHMO Just go with the lowest cost versions you can find but stay away from the foreign stuff .
Wow, so many shops had a stab at it lol.
(I think they need to do a course on engine management logic). Who could supply that 😀.
So in open loop mode the computer is using default settings that are close enough to allow it to run?.
The second it has sensors, logic hell breaks loose lol, plus any vaccume leaks/breaches could confuse matters.
Strong smell of gas suggests that O2 sensors are not incorrect/defective and exhaust really is that rich. Cat on Bank 1 could be compromised as a result. So that may need to be replaced, depending on results of pressure testing. But why is exhaust rich? Insufficient spark? Test those aftermarket ignition coils. Looking forward to part 2.
Watched first 9 minutes, my first educated guess would be stuck open Evap Purge Valve ? Fuel droplet's and vapors steady drawing into the intake manifold....
I have seen excessive plug gap ( by a DIYer) cause problems. I wonder what would happen if some were correct and some wrong?
I'm at 9:35 and I'm thinking Temp sensor. He just said it was at 109F... cold (and really rich)... engine thinks it's in warm-up. Let's see...