The Official Jeep Wrangler TJ Oxygen (O2) Sensor Thread

Mike Z

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Since NGK has discontinued the 23151 for 1997-1999 4.0 Upstream sensor, has anyone found a good replacement for this? I can not find one in stock anywhere.

I just purchased a 23131 as eBay states its the same thing, but I will report back if there are any issues.

This site is pretty random, but they carry dodge/chrysler parts. They have the 23151 in stock...according to their site.


1666110677103.png
 

reddvltj

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Hey @Chris , it looks as though NGK/NTK dropped the numbers for the 1997 -1999 and 2000 model year Jeeps with the 4.0 and 2.5.

I called their advanced support and the gentleman explained to me that they are going through a "redesign" and that there "should be" new numbers for those years "sometime" in the near future.
 
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Mike Z

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Hey @Chris , it looks as though NGK/NTK dropped the numbers for the 1997 -1999 and 2000 model year Jeeps with the 4.0 and 2.5.

I called their advanced support and the gentleman explained to me that they are going through a "redesign" and that there "should be" new numbers for those years "sometime" in the near future.

Nice work. Thanks for posting.
 
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reddvltj

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Nice work. Thanks for posting.

Thanks, their tech support has always been pretty helpful when ever I call them. It's too bad they didn't have a more definitive release date for the new #s or any option to be put on some kind of a notification list. I know this thread has helped a LOT of people and will continue to do just that, so long as NGK/NTK doesn't completely abandon those of us that have 20+ year old rigs.

Just to make it easier for anyone who wants it, here's their tech contact number and extensions.
1666125691098.png
 
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Chris

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Hey @Chris , it looks as though NGK/NTK dropped the numbers for the 1997 -1999 and 2000 model year Jeeps with the 4.0 and 2.5.

I called their advanced support and the gentleman explained to me that they are going through a "redesign" and that there "should be" new numbers for those years "sometime" in the near future.

Thanks for letting me know. I’m going to remove the 97-00 model years from the original post until they get it sorted out.
 

reddvltj

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Thanks for letting me know. I’m going to remove the 97-00 model years from the original post until they get it sorted out.

I would leave them up for reference, at least for now, because some places still have them in stock. Maybe just notate that they may harder to find for now???
 

jonlandrum

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So I'm replacing mine, and I definitely needed the sledge on one of the lower ones, but the two upper sensors were so loose they might have been able to work themselves out in a couple more trips. Literally 0 ft. lbs. of torque. Hand tightening would have been better. So even if you're not planning to replace them yet, at least have a look at them to make sure they're actually "bad" bad, and not just dangling off to the side somewhere.
 
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Shuttlesworth

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Since NGK has discontinued the 23151 for 1997-1999 4.0 Upstream sensor, has anyone found a good replacement for this? I can not find one in stock anywhere.

I just purchased a 23131 as eBay states its the same thing, but I will report back if there are any issues.

Reporting back on this. The 23131 is not a replacement for the 23151. The connectors look very close, but some of the marking on the housings are different. But more importantly, the sensor ends do not match. I am returning the 23131 to amazon and will be ordering off the Napa link if there are still some in stock.
 

Mike Z

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Reporting back on this. The 23131 is not a replacement for the 23151. The connectors look very close, but some of the marking on the housings are different. But more importantly, the sensor ends do not match. I am returning the 23131 to amazon and will be ordering off the Napa link if there are still some in stock.

Hopefully there is stock. The guy I spoke with at Napa said that there were still quite a few. He did a multi-state search. Thanks for reporting back and confirming that the 23131 is not a match for the 23151.
 
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aslupecki

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Hi all - this site is amazing and has been a great help to me. I recently was getting the P1037 code so I replaced the bank 1/pos 2 sensor ordered from Amazon using the part number and link on the first page of this thread. I then started getting a P1038 and P2098. After researching here, I replaced the other sensors as PM, with no change. I remembered the first sensor came in a clear plastic bag w a white label and the other three all came in green NTK factory sealed boxes. So, I re-ordered another NTK 23159 and it arrived in factory packaging this time. I reinstalled and so far, so good. I have them side by side in the pic and they're clearly not the same sensor. The genuine NTK is on the right with factory packaging. Lesson learned - make sure you get factory packaging or return. As it says many times in this thread, you only want NTK.

IMG_8369.jpg
 
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jonlandrum

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Hi all - this site is amazing and has been a great help to me. I recently was getting the P1037 code so I replaced the bank 1/pos 2 sensor ordered from Amazon using the part number and link on the first page of this thread. I then started getting a P1038 and P2098. After researching here, I replaced the other sensors as PM, with no change. I remembered the first sensor came in a clear plastic bag w a white label and the other three all came in green NTK factory sealed boxes. So, I re-ordered another NTK 23159 and it arrived in factory packaging this time. I reinstalled and so far, so good. I have them side by side in the pic and they're clearly not the same sensor. The genuine NTK is on the right with factory packaging. Lesson learned - make sure you get factory packaging or return. As it says many times in this thread, you only want NTK.

View attachment 372569

For future reference, Rock Auto is probably cheaper than Amazon, and no issues with misbranded parts.
 

aslupecki

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For future reference, Rock Auto is probably cheaper than Amazon, and no issues with misbranded parts.

Hi all - this site is amazing and has been a great help to me. I recently was getting the P1037 code so I replaced the bank 1/pos 2 sensor ordered from Amazon using the part number and link on the first page of this thread. I then started getting a P1038 and P2098. After researching here, I replaced the other sensors as PM, with no change. I remembered the first sensor came in a clear plastic bag w a white label and the other three all came in green NTK factory sealed boxes. So, I re-ordered another NTK 23159 and it arrived in factory packaging this time. I reinstalled and so far, so good. I have them side by side in the pic and they're clearly not the same sensor. The genuine NTK is on the right with factory packaging. Lesson learned - make sure you get factory packaging or return. As it says many times in this thread, you only want NTK.

View attachment 372569

So premature celebration ... my CEL came back on. It took longer, but did come on. I am getting a confirmed P2098 - Post catalyst Fuel Trim System too Lean, plus pending on P0153 - O2 sensor circuit slow and P0157 - O2 sensor low voltage. I replaced three sensors, but was unable to break free bank 2 / sensor 2 on the exhaust past the pre-cat. So, I can take another run at that this weekend & double check tightness and connections on the other three. Any other suggestions or things to check with this combo?
 

jonlandrum

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So premature celebration ... my CEL came back on. It took longer, but did come on. I am getting a confirmed P2098 - Post catalyst Fuel Trim System too Lean, plus pending on P0153 - O2 sensor circuit slow and P0157 - O2 sensor low voltage. I replaced three sensors, but was unable to break free bank 2 / sensor 2 on the exhaust past the pre-cat. So, I can take another run at that this weekend & double check tightness and connections on the other three. Any other suggestions or things to check with this combo?

That same sensor was difficult for me to remove, also. Someone in this thread mentioned spraying it with penetrating fluid (something like PB Blaster or Liquid Wrench), let that sit overnight, then crank the engine and let it run for about ten minutes to warm the joint up. Heating the joint causes the metal to expand, loosening the threads and potentially breaking the seize. After you turn the engine off, get a breaker bar---not your ratchet---and try removing the sensor again.

After you install the new sensor, unplug the negative battery cable for the rest of the day (like eight hours or so), then plug it back in and go for a drive. The technique I used was ten minutes of city driving (up to 35 mph stop-and-go), ten minutes of highway driving (55--60 mph min/max; don't get out of that range), and ten minutes of city driving back home (up to 35 mph stop-and-go). After that, you should be good to go.
 
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reddvltj

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After you install the new sensor, unplug the negative battery cable for the rest of the day (like eight hours or so), then plug it back in and go for a drive. The technique I used was ten minutes of city driving (up to 35 mph stop-and-go), ten minutes of highway driving (55--60 mph min/max; don't get out of that range), and ten minutes of city driving back home (up to 35 mph stop-and-go). After that, you should be good to go.

Or, if you live close enough to (most) major auto parts stores, they generally have scan tools that can clear the code for you.

200.gif
 

jonlandrum

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Or, if you live close enough to (most) major auto parts stores, they generally have scan tools that can clear the code for you.

View attachment 373432

Well, yes, and an ODB adapter is like $5 on eBay. The point of this process isn't to clear the code, it's to reset the computer's memory of how your engine runs and forces it to relearn what the mixture should be. It will do that process on its own over time, but that can take upwards of 500 miles before it settles into the right mix.
 
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aslupecki

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Thanks all. I have an app on my phone and an OBD reader that can clear the codes & I have done that after replacing the three sensors. But, they keep coming back. I tried clearing again and have the P0153 and P2098 pending after driving to work and back today (~40 miles round trip). I thought that clearing with the tool was roughly equivalent of removing the battery to clear. Can you tell me more about this computer memory thing? I like to understand what I am doing and why. Thx.
 
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jonlandrum

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Thanks all. I have an app on my phone and an OBD reader that can clear the codes & I have done that after replacing the three sensors. But, they keep coming back. I tried clearing again and have the P0153 and P2098 pending after driving to work and back today (~40 miles round trip). I thought that clearing with the tool was roughly equivalent of removing the battery to clear. Can you tell me more about this computer memory thing? I like to understand what I am doing and why. Thx.

Sorry, just seeing this. I pieced together the information from a number of different Jeep forums, but the two main threads where I found this were these: