I had a misfire issue a week ago. Had noticed reduced power for a while but never felt the misfire until last week. I hooked my scan tool up to read live data. Cylinder #3 was the only one registering misfires. I swapped the plug and coil. Misfire remained on #3. Swapped wires and the misfire moved so I replaced the wires with the factory Delcos. Truck smoothed out and has more power. Hooked up my scan tool just for giggles. Now it has a random misfire the misfires twice on randomized cylinders. It went from 1600 misfires on # 3 to 2 misfires on 1 , 3, 5 ,6 & 4. Can’t feel it but it registers 2 and it’s gone to a different cylinder. I was watching my upstream 02 sensors jump all over the place from over one down to .015! I didn’t think 02 sensors were supposed to move that much. I bought 2 upstream O2 sensors since they are cheap and mine are the originals that are 14years old and have 143k miles on them. Hopefully they help. It’s just strange how it went from many misfires on one cylinder and the 2 misfires on randomized cylinders. 🤔
Here are some few dead give away that it’s an 02 sensor. 1) The code is accompanied by “Lean” code. Car tends to run better from start up when cold and gets really bad once it’s warmed up. Let me explain. The O2 sensor at this point is defective but not defective enough for the computer to send an 02 sensor code because the signal is still within range except it’s very inaccurate, and sending the computer a reading that is extremely lean and computer respond by enriching the mixture so much so that it fouls up the plug because computer respond by enriching the mixture when it should not. Changing the plug will cure problem for a short time maybe a few minutes Plug fouls up again after and misfire start to get worse. The reason why it’s better when engine is cold is because the computer runs the mixture on default. Once it warms up and goes into closed loop computer then runs mixture based on 02 sensor input which is wrong info (lean) so computer does not know any better it’s a (computer not a person) and dumps more gas fouling up plug and also causing incomplete combustion. NOTE you may not even have an 02 sensor code just a lean code because at this point the data from 02 sensor is still within range for computer to set a code, it’s just giving the computer a wrong info. The mixture of air/gasoline is a very delicate balance and it does not take much to make your engine do some F up shit. To finalize this you may ask why engine runs fine when 02 sensor code is thrown. Well that’s because I because when the the computer sense the 0/ sensor is defective it runs in default and ignore input from 02 sensor input (engineers are smart aren’t they? ) But …….. if the computer is getting false reading from 02 sensor but it also does not know that it’s really defective that things go haywire (engineers were not smart after all, but modern car computer now a days are much more advanced so I doubt newer car don’t have this problem anymore) So there you go. Problem like these are more common on older vehicle. Vehicle I ran into this problem so far is Saturn, GM trucks, dodge trucks, and some Chrysler vehicle usual early 2000 models. Courtesy of Green Power Automotive in Houston Tx. We service Hybrid, Electric cars and do some deep Diagnostics and repair on Normal Vehicles that other shop can’t figure out. Most of my customer are other shops around the area.
You must be correct! I have been dealing with a misfire problem in my 06 Hummer H3 with the 3.5l i5 and I have changed plugs, coils injectors, intake manifold gaskets and even the VVT selonoid and I am still misfiring with codes!!!? The last piece of the puzzle is the O2 sensors and I have to wait until Thursday to find out!???
I'm currently getting bank 2 misfires on my Honda Pilot. Long story short, timing belt idler pulley bolt broke and valves were damaged. I made the necessary repairs but, I get misfires for all cylinders in that bank. Compression is good, fuel injectors have been individually cleaned and tested. Still have the problem so, I am going to replace the upstream O2 sensor. One it has 240K miles on it and two, I think the nasty fuel/carbon gunk during the breakdown may have contaminated the sensor. As bad as the intake and cylinders were, I am hoping that is my problem. Just wanted to share in hopes it helps others. Thanks for this video.
@@c.p.5741 Yes. However, I still get an error for a non efficient catalytic converter. At 250K now and I will just keep driving it. Still gets the average 20 MPG like it always has.
@@c.p.5741 That's what I think as well. All in all, the repair was about the cost of a one/two month new car payment. Thank goodness I can do the work. Hopefully it last long enough to get my daughter through 2 more years of college.
@@rkshell1975 thank you for the infos. I have same problem in bank 2 S1. obd2 read b2s1 (1.27) high and p0152 pending then after mintes got p0300 ( surprise me because had just changed all sparks plugs and coils. But after first coming is p0152 then p0300 later and car rough idke. Tomorrow will change b2s1 sensor. Thank you
@@appliancedude63 no it did not. But we found the problem: the sensor that I bought online was universal ( even if the seller said it will fit). did not work properly and I bought 4 off them, I did try 3 of them, but did not work ans still getting the error code with engine light. So we bought tge manifactory original sensor...Boom it did work.. reading perfect and problem solved... So buy original sensor and try it
Hopefully this works for me, I have spark and fuel, but bank 2 side cylinders 2468 are misfiring, I can pull the plug wires off the coil pack and engine doesn't even hesitate, been pulling my hair out
I had a misfire issue a week ago. Had noticed reduced power for a while but never felt the misfire until last week. I hooked my scan tool up to read live data. Cylinder #3 was the only one registering misfires. I swapped the plug and coil. Misfire remained on #3. Swapped wires and the misfire moved so I replaced the wires with the factory Delcos. Truck smoothed out and has more power. Hooked up my scan tool just for giggles. Now it has a random misfire the misfires twice on randomized cylinders. It went from 1600 misfires on # 3 to 2 misfires on 1 , 3, 5 ,6 & 4. Can’t feel it but it registers 2 and it’s gone to a different cylinder. I was watching my upstream 02 sensors jump all over the place from over one down to .015! I didn’t think 02 sensors were supposed to move that much. I bought 2 upstream O2 sensors since they are cheap and mine are the originals that are 14years old and have 143k miles on them. Hopefully they help. It’s just strange how it went from many misfires on one cylinder and the 2 misfires on randomized cylinders. 🤔
This has been a suspicion. I'll do this tomorrow. Hopefully, this is the problem. Thanks for the insight!
Great description of where the sensors are located . I'm good now thanks
Here are some few dead give away that it’s an 02 sensor. 1) The code is accompanied by “Lean” code. Car tends to run better from start up when cold and gets really bad once it’s warmed up. Let me explain. The O2 sensor at this point is defective but not defective enough for the computer to send an 02 sensor code because the signal is still within range except it’s very inaccurate, and sending the computer a reading that is extremely lean and computer respond by enriching the mixture so much so that it fouls up the plug because computer respond by enriching the mixture when it should not. Changing the plug will cure problem for a short time maybe a few minutes Plug fouls up again after and misfire start to get worse. The reason why it’s better when engine is cold is because the computer runs the mixture on default. Once it warms up and goes into closed loop computer then runs mixture based on 02 sensor input which is wrong info (lean) so computer does not know any better it’s a (computer not a person) and dumps more gas fouling up plug and also causing incomplete combustion. NOTE you may not even have an 02 sensor code just a lean code because at this point the data from 02 sensor is still within range for computer to set a code, it’s just giving the computer a wrong info. The mixture of air/gasoline is a very delicate balance and it does not take much to make your engine do some F up shit. To finalize this you may ask why engine runs fine when 02 sensor code is thrown. Well that’s because I because when the the computer sense the 0/ sensor is defective it runs in default and ignore input from 02 sensor input (engineers are smart aren’t they? ) But …….. if the computer is getting false reading from 02 sensor but it also does not know that it’s really defective that things go haywire (engineers were not smart after all, but modern car computer now a days are much more advanced so I doubt newer car don’t have this problem anymore) So there you go. Problem like these are more common on older vehicle. Vehicle I ran into this problem so far is Saturn, GM trucks, dodge trucks, and some Chrysler vehicle usual early 2000 models. Courtesy of Green Power Automotive in Houston Tx. We service Hybrid, Electric cars and do some deep Diagnostics and repair on Normal Vehicles that other shop can’t figure out. Most of my customer are other shops around the area.
Thank you very much for the info
You must be correct! I have been dealing with a misfire problem in my 06 Hummer H3 with the 3.5l i5 and I have changed plugs, coils injectors, intake manifold gaskets and even the VVT selonoid and I am still misfiring with codes!!!? The last piece of the puzzle is the O2 sensors and I have to wait until Thursday to find out!???
Did it work out for you?
I'm currently getting bank 2 misfires on my Honda Pilot. Long story short, timing belt idler pulley bolt broke and valves were damaged. I made the necessary repairs but, I get misfires for all cylinders in that bank. Compression is good, fuel injectors have been individually cleaned and tested. Still have the problem so, I am going to replace the upstream O2 sensor. One it has 240K miles on it and two, I think the nasty fuel/carbon gunk during the breakdown may have contaminated the sensor. As bad as the intake and cylinders were, I am hoping that is my problem. Just wanted to share in hopes it helps others. Thanks for this video.
Did the new sensor stop the misfire?
@@c.p.5741 Yes. However, I still get an error for a non efficient catalytic converter. At 250K now and I will just keep driving it. Still gets the average 20 MPG like it always has.
@@usnchief1339 okay good! As long as the performance of the vehicle is good you should be fine! 👍
@@c.p.5741 That's what I think as well. All in all, the repair was about the cost of a one/two month new car payment. Thank goodness I can do the work. Hopefully it last long enough to get my daughter through 2 more years of college.
@@usnchief1339 I pray so 🙏
I agree with o2 sensor causing a multiple cylinder misfire, been down this road several times with my fleet of gmc sierras..
Dealing with literally the exact problem right now down to the exact codes... new sensors coming tomorrow, 03 sierra 5.3.
Did it fix the random misfires ?
Yes
@@rkshell1975 thank you for the infos.
I have same problem in bank 2 S1. obd2 read b2s1 (1.27) high and p0152 pending then after mintes got p0300 ( surprise me because had just changed all sparks plugs and coils.
But after first coming is p0152 then p0300 later and car rough idke.
Tomorrow will change b2s1 sensor.
Thank you
@@DERONIYA did it work out for you?
@@appliancedude63 no it did not. But we found the problem: the sensor that I bought online was universal ( even if the seller said it will fit). did not work properly and I bought 4 off them, I did try 3 of them, but did not work ans still getting the error code with engine light. So we bought tge manifactory original sensor...Boom it did work.. reading perfect and problem solved...
So buy original sensor and try it
Anybody gonna comment on the tower of power fans? Holy crap my man!!
Idkbif I missed it, but did you have JUST a p0300 or did you have actual o2 codes prior to the repair?
Hopefully this works for me, I have spark and fuel, but bank 2 side cylinders 2468 are misfiring, I can pull the plug wires off the coil pack and engine doesn't even hesitate, been pulling my hair out
That scanner gives you live misfire data?