Jeep TJ O2 Sensor Guide (Symptoms, Codes, Replacement & Fixes)

[Bobbycat83]

I have a 2004 4.0 6cyl and it appears to only have 2x o2 sensors. This is from a TJ sold in australia so I’m guessing we have different laws regarding emissions.

Can anyone shed some light on which sensors I need to buy to replace my existing ones?

You are correct, export TJs only ever came with 2, O2 sensors. I know some where in this thread the subject has been brought up few times. Unfortunately I can't tell you a page or a post number to look for... I know there are some other members that hail from down under that might be able to point you in the right direction.

I guess this is the same as a federal emission 4.0 configuration , only with one cat.
I am prior to change my sensor And I also want to be sure . I also have two sensors only configuration in Europe. That correspond to federal emisións. All exported TJs where federal I guess.

Someone knows exactly what walker ref does the federal emissions have?

I bought ref 250-24943 for Upstream
And 250-24942 for downstream m

But I dont want to take out the old sensor, broke it or something and then have problems with the new one. Because being in Spain is not easy in case it start giving me problems.

So if someone with one cat have changed them recently would be great to know feedback and exact ref to be sure.


Thanks a lot

 

[reddvltj]

I guess this is the same as a federal emission 4.0 configuration , only with one cat.
I am prior to change my sensor And I also want to be sure . I also have two sensors only configuration in Europe. That correspond to federal emisións. All exported TJs where federal I guess.

Someone knows exactly what walker ref does the federal emissions have?

I bought ref 250-24943 for Upstream
And 250-24942 for downstream m

But I dont want to take out the old sensor, broke it or something and then have problems with the new one. Because being in Spain is not easy in case it start giving me problems.

So if someone with one cat have changed them recently would be great to know feedback and exact ref to be sure.


Thanks a lot

OK DOWN THE RABBT HOLE I GO!!!!!!

This is for all you EXPORT TJ owners... with a 2000 model year ONLY!!! I didn't look up any other years... Feel free to do your own research NTK has a WONDERFUL cross reference guide. This isn't that hard, it's just a little time consuming.

https://www.ngk.com/using-the-ngk-cross-reference

The OEM Mopar numbers listed on RockAuto cross referenced to NTK and then to Walker all come back as the same actual sensor with differing wire lengths. So in most (if not all) circumstances the sensor with the longer wire will work for both up stream and down stream positions.

Here are the OEM numbers

56041213AG cross references to 2 NTK numbers

and 56041676AA crosses to

Notice that BOTH OEM Mopar numbers eventually cross to the same number NTK 23179 which crosses to a Walker 250-24942.

You can use the 250-24942 in both upstream and downstream positions.



Here's how the 3 compare.

 

[Bobbycat83]

@reddvltj you’re awesome , your explanation is superb!
Promess I checked or tryed to check but at the end , I had always doubts.
I didn’t know either sensor, or all sensors despite the length of the cable are the same or works the same in either position . I thought that the sensor itself was different if it was upstream or downstream.

Before these my conclusion was that my upstream should be the walker 24943, don’t remember why. But now is clear that it is also valid or the correct one is the 24942, I have both so will check length of the cable just in case and would be done.

Thanks again for your clear and detailed explanation.
Hope walker sensors don’t give me problems . At the time when I bought them there wasn’t ntk available.

 

[reddvltj]

@reddvltj you’re awesome , your explanation is superb!
Promess I checked or tryed to check but at the end , I had always doubts.
I didn’t know either sensor, or all sensors despite the length of the cable are the same or works the same in either position . I thought that the sensor itself was different if it was upstream or downstream.

Before these my conclusion was that my upstream should be the walker 24943, don’t remember why. But now is clear that it is also valid or the correct one is the 24942, I have both so will check length of the cable just in case and would be done.

Thanks again for your clear and detailed explanation.
Hope walker sensors don’t give me problems . At the time when I bought them there wasn’t ntk available.

Just FYI, if the Walkers end up not working out for you NTK still shows the NTK 23179 still available on their website and there are multiple other vendors that stock it.

 

[Bobbycat83]

Just FYI, if the Walkers end up not working out for you NTK still shows the NTK 23179 still available on their website and there are multiple other vendors that stock it.

Yeah will try and if not will go for the 23179 , thanks a lot my friend

 

[Captain Phoenix]

Given that NGK / NTK O2 sensors are now being discontinued

Rock Auto currently has the oxygen sensors for the 2005 in stock so I just ordered a set as spares with my order of Moog control arm bushings. I replaced them all when I did the catalytic converter back in 2020 so I'm hopefully good for a long while but now I have a set just in case.

 

[freedom_in_4low]

- NTK 23160 (upstream, cyl. 4-6, bank 2 / sensor 1)
- NTK 23195 (upstream, cyl. 1-3, bank 1 / sensor 1) - this is the "newer" version of NTK 23018, the only one offered from RockAuto.

I can't find a good reason for why it would be a problem but it makes my brain itch that they've superseded the 23018 with the "improved" 23195 which differs significantly in appearance where the exhaust gases surround the sensing element, but left bank 2 with the old design 23160.

"new and improved"

vs what the "old" design 23018 looks like (photo is of the 23160 bank 2 sensor so the cable/connector is wrong but the bulb tip matches)

It's so tempting to go find a 23018 on a parts store shelf somewhere just so they match but I already have an opened 23195 and don't want to deal with the hassle of a RockAuto return. I wouldn't think anything of it in the past but it's 2026 and everything is being enshittificated and it seems more often than not that "new" versions of stuff are just ways the manufacturer found to increase margin.

No action items here, just griping.

 

[LJBean]

I very much doubt that it is "improved" since Jeep doesn't provide any support for the TJ anymore. You are probably right that the 23018 may have been cancelled due to lack of cross-matching and they have found what they consider to be a comparable replacement that works with more applications.

I have all 4 stock replacements on the shelf due to the disappearing stock parts for the TJ.