Hey guys. We member here. Have a question. 2005 Jeep Wrangler 4.0. I’m getting a P0031, 37,51,57. All hit at once. It’s 02 sensor heat Circut’s or something. Jeep only has 50,000 original miles. Runs great. But this is really irritating me. I checked the wiring. Seen no issues. But I know all 4 02 sensors didn’t go bad at the same time. Anyone have this issue and a fix? Thanks in advance!
O2 sensor codes for all 4 sensors at once
- Thread starter Motolife448
- Start date
First off, that's a damn nice TJ! Absolutely love the red, and it looks clean as hell.
That is pretty odd you'd be getting codes for all the O2 sensors at once. Usually when something like that happens, I suspect it's the pre-cats going bad or clogged (that's a fairly common issue on these older TJs).
Are the O2 sensors the factory O2 sensors, or do you know if they've ever been replaced?
Have you tried clearing the codes to see if the continue to come back?
That is pretty odd you'd be getting codes for all the O2 sensors at once. Usually when something like that happens, I suspect it's the pre-cats going bad or clogged (that's a fairly common issue on these older TJs).
Are the O2 sensors the factory O2 sensors, or do you know if they've ever been replaced?
Have you tried clearing the codes to see if the continue to come back?
Thank you! Yes I have cleared it. Stayed off a few days then back. Now even clearing it with a scanner it comes right back on instantly. Scanner said something about “fault in ground” still 02 heat Circut related. All 4 sensors tho which is what’s weird. I looked and the wiring looks fine. I would assume they’re original sensors. The Jeep only has 50,000 original miles on it. I do all my own work for the most part, but this is really stumping. I googled it as well to see what others have said and it seems to be a bad issue at times. Possibly with the computer even. Hopefully not.
With 50k miles they should be original.
Since it's saying fault in ground, I suspect it is something wiring related that you might just have to dig further to find. All it takes is the tiniest break in a wire, sometimes there' a pain in the butt to see.
It could be PCM related, yes. However, I wouldn't jump to that conclusion yet, as that's a $1000 fix for a replacement PCM.
It might be worth it to just try replacing all the O2 sensors (if you do, don't use anything but NGK, otherwise they are known to cause issues), just given how cheap it is for 4 of them.
It might not clear the codes, but it's certainly a cheaper test than replacing the PCM.
This thread may or may not come in handy:
The Official Jeep Wrangler TJ Oxygen (O2) Sensor Thread
Since it's saying fault in ground, I suspect it is something wiring related that you might just have to dig further to find. All it takes is the tiniest break in a wire, sometimes there' a pain in the butt to see.
It could be PCM related, yes. However, I wouldn't jump to that conclusion yet, as that's a $1000 fix for a replacement PCM.
It might be worth it to just try replacing all the O2 sensors (if you do, don't use anything but NGK, otherwise they are known to cause issues), just given how cheap it is for 4 of them.
It might not clear the codes, but it's certainly a cheaper test than replacing the PCM.
This thread may or may not come in handy:
The Official Jeep Wrangler TJ Oxygen (O2) Sensor Thread
I have had the same issue for the past five years, except code numbers 0032, 0038, 0052, and 0058. It has to be heat related for me as it only happens during the summer and by the time September rolls around the codes go away until the following June/July.
All O2 sensors were swapped, and I had a dealership and two Indys look at the problem. The conclusion was a bad PCM from my local emissions shop.
A clogged cat could also be a possibility, but my emissions shop ruled that out for my problem.
This summer the codes triggered in early July and they are still around today, a couple times they disappeared for a day or two, but they are present today.
All O2 sensors were swapped, and I had a dealership and two Indys look at the problem. The conclusion was a bad PCM from my local emissions shop.
A clogged cat could also be a possibility, but my emissions shop ruled that out for my problem.
This summer the codes triggered in early July and they are still around today, a couple times they disappeared for a day or two, but they are present today.
Same codes for mine changed all 4 sensors used ntk sensors code came back. Changed gas cap codes came back. Cleaned ground strap on engine block fixed problem
Thanks - Good to know as I may try that, and I actually ordered all new cables but have not had time to install.
Since mine appears to only occur during summer months, would you attribute that to a bad ground, I am trying to rationalize this, why do the codes go off on my vehicle only during summer months.
Yes I think so mine did same thing mostly in summer and that’s when inspection was due in July and last year it came on and went off on its own with no reset but this year it repeatedly turned on and would not stay off. I think my old sensors were good but I have changed them now and will leave new ones on. Try this first. Unhook positive battery cable first. Then clean #105 ground attach pos battery cable drive a 50 mile cycle and see if codes stay off.
Let me know if this fixed yours if I had done this first I’m sure I would have saved $$$ on new sensors
I will be doing this over the weekend and report back. Thank you!
Matt888
TJ Enthusiast
This is too funny I was searching the web and found this thread and we now own this Jeep, 2 years later still all 4 O2 sensor codes, I may buy a computer from Wranglerfix for it sometime. But still looks great and runs great.
That is hilarious!
I always had those four O2 codes, for like 6 years, and then recently my oil pan was leaking so the exhaust pipes had to be removed in order to install a new oil pan. Now I only have only one error code, 0431.
It's a very odd situation, but I never found it to be an issue, just annoying to see the CEL on all the time.
Matt888
TJ Enthusiast
Matt888
TJ Enthusiast
Will check the ground 105 wire like stated above just to see if it is something simple. Has 74k miles on it now.
wittel55
New Member
Hey there I am experiencing identical issues with my LJ . Check engine light all 4 o2 sensor codes and they do not come on in winter. I replaced the exhaust and have replaced the sensors. I am curious if you ever fixed your issue ? Thanks
Ugh, no, and my emissions test was due last month so I need to figure this out of before I lose my registration...and as you said, around October is when they will mysteriously go away. Heat is the issue but I have no idea why.
Over the weekend I added the stuff in the link below (could be snake oil for all I know), but I really believe that the PCM is the issue and @Wranglerfix has the solution. Problem is, with a manual tranny the new PCM is $1.2k so I am trying to avoid that expense since this issue is cosmetic, no Jeep issues whatsoever are caused by this, but if I cannot pass emissions I may have to do it. If you have an auto tranny then the cost is not so bad. Mark, I love your fix and have had a great conversation.
https://motorkote.com/products/catalytic-exhaust-treatment
https://wranglerfix.com/
wittel55
New Member
have you considered using a company like this ? I might give them a shot
https://siaelec.com/product/jeep-ecm-ecu-repair-return/
https://siaelec.com/product/jeep-ecm-ecu-repair-return/
Yes I have, if you read online reviews and stuff on the forums, these shops get terrible reviews. In most cases they just send you someone else's broken PCM or they attempt to fix it but can't. In any event, the issue is the stock PCM as the electrical connections break down, and there is no real fix, and that is where Wrangler fix came into play. They send you a non-Jeep PCM that works, and lasts. Tons of great reviews, essentially no negative reviews on his product.
What year is your Jeep and which tranny does your your Jeep have?
You should call Mark at Wrangler fix and discuss, reserve an hour or so as he is a great guy to speak with.
wittel55
New Member