O2 sensor codes for all 4 sensors at once

just curious if your check engine light issue was fixed with the new PCM .... mine is currently off since the weather has cooled down but I still want it fixed permanently

My original PCM has been reinstalled and the error code came back - no longer the four O2 sensor codes, now it's a 0431. I should be able to drop off at the mechanic in January and hopefully he can solve this one.

What's crazy is my emissions test center went through everything, they kept the Jeep for 24 hours and concluded it was the PCM.
 
damn.... well since its been cold my light has been off so what are you gonna do? I had mine inspected and cleared emissions too what did the wrangler fix guy say?
 
damn.... well since its been cold my light has been off so what are you gonna do? I had mine inspected and cleared emissions too what did the wrangler fix guy say?
Internal PCM issues can most definitely be caused by changes in temperature. When it's warmer out the PCM can be shorting out internally vs when the weather is cooler. One thing I use when diagnosing internal ECM/PCM problems due to heat is something like this,

https://www.chemtronics.com/freeze-spray-2
CRC also makes a similar product.
 
damn.... well since its been cold my light has been off so what are you gonna do? I had mine inspected and cleared emissions too what did the wrangler fix guy say?

Just following up as I decided to remove my cats and check them out. Clearly the cat was the issue. I have not installed the new cats yet but based on these pics I assume it is.

One is the front cat and the other is the rear.
IMG_20220424_163407.jpg

IMG_20220424_163413.jpg
 
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Was it the cats?? I stumbled on this thread and have had CEL for all 4 O2’s for t least 6 years. Rubi runs fine otherwise, go figure. ¯\_(ツ)_/¯
 
Was it the cats?? I stumbled on this thread and have had CEL for all 4 O2’s for t least 6 years. Rubi runs fine otherwise, go figure. ¯\_(ツ)_/¯

It’s almost certainly either the cats or a short in the wiring.
 
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Was it the cats?? I stumbled on this thread and have had CEL for all 4 O2’s for t least 6 years. Rubi runs fine otherwise, go figure. ¯\_(ツ)_/¯
I was having the same O2 codes for several years that were not fixed by the previous owner replacing all the O2 sensors. One of the pre-cats finally catastrophically failed on the highway. Its internal parts blew downstream and plugged the main cat enough to drop my top speed to 4-5 mph in about a quarter mile. Replacing all three cats cured all the O2 sensor codes and the engine ran a lot better afterwards too.
 
Was it the cats?? I stumbled on this thread and have had CEL for all 4 O2’s for t least 6 years. Rubi runs fine otherwise, go figure. ¯\_(ツ)_/¯

Are you driving an auto or manual? It's what Chris said, blown cat or short in the wiring. I had the same issue, and I bought a magnaflow three cat exhaust system to replace my current exhaust. I did this over about 8 months ago and all has been good. One of my cats disintegrated so that was is.

It sucks to take the exhaust system off if the Jeep is your primary vehicle, but if you have the time I would take it off to inspect. And, if a cat is blown, you could then bring the exhaust to a muffler shop to have new cats welded in.

It’s almost certainly either the cats or a short in the wiring.

+1 to the man banned from Paypal :)
 
I know I sound dogmatic , but the 05-06 models seem prone to have evap, 02 sensor and cat issues at some point- I consider the oxygen sensors a normal wear item anytime around 70 to 80,000 miles-

This is not a hard fact- it’s just one of my “ andy theories” That I have like the people at the next table at the restaurant look like they’re going to be getting a divorce in the next 3-4 months, and all the other wild ideas I come up with I’m just dead sure about.
 
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Hey everyone. So have an 08 Jeep wrangler Throwing a P038 code bank one sensor downstream, O2 sensor driver side. I have purchased an O2 sensor from everywhere, including the dealership and continue to get the same code. As you all may know both downstream O2 sensors on this vehicle identical, so what I did is swap them and now I’m getting a code on bank two sensor 2 no matter what O2 sensor I put on it. has anyone else been into this issue?
 
Hey everyone. So have an 08 Jeep wrangler Throwing a P038 code bank one sensor downstream, O2 sensor driver side. I have purchased an O2 sensor from everywhere, including the dealership and continue to get the same code. As you all may know both downstream O2 sensors on this vehicle identical, so what I did is swap them and now I’m getting a code on bank two sensor 2 no matter what O2 sensor I put on it. has anyone else been into this issue?

This forum and it's members are TJ Wrangler oriented. You'll have better luck in a JK specific forum.
 
Hey everyone. So have an 08 Jeep wrangler Throwing a P038 code bank one sensor downstream, O2 sensor driver side. I have purchased an O2 sensor from everywhere, including the dealership and continue to get the same code. As you all may know both downstream O2 sensors on this vehicle identical, so what I did is swap them and now I’m getting a code on bank two sensor 2 no matter what O2 sensor I put on it. has anyone else been into this issue?

Wrong forum. This is a forum for 1997-2006 TJs. You have a JK.

You want https://wranglerjkforum.net/
 
I was having the same O2 codes for several years that were not fixed by the previous owner replacing all the O2 sensors. One of the pre-cats finally catastrophically failed on the highway. Its internal parts blew downstream and plugged the main cat enough to drop my top speed to 4-5 mph in about a quarter mile. Replacing all three cats cured all the O2 sensor codes and the engine ran a lot better afterwards too.

@Jerry Bransford Jerry which O2 codes were you getting?

I have all 4 O2 Heater sensor codes ‘ O2 Heater control Low”, P0031, P0037, P0051, P0057 and debating whether to try the PCM or not. Since these codes pop up immediately after ignition on ( not started) and a code clear, I’m thinking that would not be caused by cats, but I’m no expert on cats.

This all started with my earlier no start problem , resolved by correcting brokengrounds on G105 , RH side of engine block. But the above O2 codes remain.

My next step is to just get the 2 new upper 02 sensors in, the lower ones are newer. Then do more wire harness voltage / ground testing on each 02 plug on harness. Will be a lot easier to use an old O2 sensor plug to test harness Plugs.

Just trying to avoid cost of new PCM if not needed.

@skrelnik If I followed your history correctly. Your low O2 heater codes were corrected with new PCM, but when you put back original PCM, they did not reappear? That one makes me wonder if there’s anything else, other than possibility of PCM being intermittent.

Jeep is an ‘06 TJ, manual, ~ 75k miles.
 
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@Jerry Bransford

@skrelnik If I followed your history correctly. Your low O2 heater codes were corrected with new PCM, but when you put back original PCM, they did not reappear? That one makes me wonder if there’s anything else, other than possibility of PCM being intermittent.

Jeep is an ‘06 TJ, manual, ~ 75k miles.

The new PCM did not work for me and actually triggered additional error codes. I sold the PCM and went back to stock. I did remove my catalytic converters and replaced with Magnaflow. One of my cats was toast and I think that created excess heat leading to the four O2 error codes. The light has not come back in quite some time because

Try removing and taking a look at your cats.

IMG_20220424_163644.jpg


IMG_20220424_163413.jpg


IMG_20220424_163407.jpg
 
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@Ebaron One of the known faults of an 05-06 pcm is o2 sensors showing bad when good. The others are rough idle, loss of cluster and stalling while driving. You can send your pcm into us and we will test it in our jeep for you as well.
 
@Ebaron One of the known faults of an 05-06 pcm is o2 sensors showing bad when good. The others are rough idle, loss of cluster and stalling while driving. You can send your pcm into us and we will test it in our jeep for you as well.

Thanks Mike! I appreciate the time you spent on phone with me when dealing with my no start issue. Once I get my other 2 sensors in and check wiring a little more, I ‘ll do the PCM test. Thanks for offering this service to us!
 
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