The Official Jeep Wrangler TJ Oxygen (O2) Sensor Thread

All though it usually isn’t a big problem, there are times I’ve replaced an O2 sensor where the threads feel damaged. If you’re concerned that you might be cross threading the new sensor this tool will allow you to “chase” the threads.

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The tool was sold for chasing spark plug threads in cylinder heads. I’ve had mine since the mid 70,s.

BTW: You know you’re getting old when you inadvertently post, “I’ve got tools older than a lot of you”
 
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I have got 2 error codes relating to O2 sensors....I’ve located all 4 thanks to the awesome diagram above...just want to confirm before I start replacing them...bank 1 is towards front of car with bank 2 towards back of car?
 
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smumustang said:
I have got 2 error codes relating to O2 sensors....I’ve located all 4 thanks to the awesome diagram above...just want to confirm before I start replacing them...bank 1 is towards front of car with bank 2 towards back of car?
Click to expand...

You got it!
 
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Quick update...I sprayed PB blaster carefully on the sensors as they were pretty rusted. Left that to work for about 8 hours...took me about an hour to change them all out. Definitely get the O2 sensor socket listed in the diagram above...I reset the error codes and the care seems to idle smoother. Definitely a success for what i would call my first big jeep repair. There may have been a few Tim “the tool man” Taylor grunts... thanks again to the diagrams and links to the correct replacement parts.
 
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Glad you got it done nice and smoothly. The most difficult part is reaching some of them, and of course getting them out if they're really corroded. You made the smart choice by putting some PB Blaster on them and letting it soak in for 8 hours. That makes the job so much easier!

And yes, the O2 sensor socket is an invaluable tool to have, not just for Jeeps, but any vehicle!
 
So if an error code reoccurs “P0431 warm up catalyst efficiency Bank 2 Below Threshold” after I replaced all 4 O2 sensors...does this mean the catalytic converter is bad? I used NTK sensors. I reset codes again to try that..but if that doesn’t work is it likely a new CC is needed?
 
smumustang said:
So if an error code reoccurs “P0431 warm up catalyst efficiency Bank 2 Below Threshold” after I replaced all 4 O2 sensors...does this mean the catalytic converter is bad? I used NTK sensors. I reset codes again to try that..but if that doesn’t work is it likely a new CC is needed?
Click to expand...

Yes, a P0431 code is usually a sign of a bad catalytic converter.
 
So I have an 04' sahara 4.0 liter 6 cylinder. It is throwing two codes. 02 sensor #1 heater. With code: P0135 and the other one says 02 sensor 2/1 heater performance. With code P0155. Which of the four sensors do I need to replace?? I have read through many posts but I'm still not sure. A little help would be greatly appreciated. I also realize I should just do all 4 at this point, but can' afford that at this time. Thanks.
 
Sam.matthew said:
So I have an 04' sahara 4.0 liter 6 cylinder. It is throwing two codes. 02 sensor #1 heater. With code: P0135 and the other one says 02 sensor 2/1 heater performance. With code P0155. Which of the four sensors do I need to replace?? I have read through many posts but I'm still not sure. A little help would be greatly appreciated. I also realize I should just do all 4 at this point, but can' afford that at this time. Thanks.
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You need to replace Bank 1, Sensor 1, and Bank 2, Sensor 2.

These are the exact O2 sensors you need for your 2004 Sahara:

NGK #23137 - Bank 1, Sensor 1 (Upstream)
NGK #23135 - Bank 2, Sensor 1 (Upstream)
 
Christy Graffeo said:
Can you tell me exactly how many O2 sensors are in a 2002 Jeep Wrangler TJ?? I can't figure out which one is bad, so I'm thinking I should just replace them all.
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There are 4 total.

You can figure out which one(s) are bad by scanning your vehicle with an OBDII scan tool and getting the error codes.
 
I have a 2000 TJ sport 4.0L. Your list has a gap from the 2 o2 system to the 4 o2 system. Mine has a build date of 8/99 and only have 1 upstream and 1 downstream. The factory sensor P/N that has never failed is 56041676AA. Orielly’s shows to use NTC 23122, which you also show as B1S1. Do you think that is correct? I have to say the stealership wants $100+ for one, but I’ve never had a problem with it even after 18 years. I just wanted to replace it as I know they become less accurate with use and I just put in a set of rebuilt injectors in an effort to maximize mpg and reliability.

Side note: the 2000 is an odd duck. I’ve noticed not a single aftermarket exhaust company has a manifold or downpipe for this year. And if they do advertise it you can clearly see the design isn’t the same. I’ve thought about just changing everything over to a different year. I also have COP and a crank sensor instead of a distributor. And my charcoal canister is still under the hood.
 
Road Works said:
I have a 2000 TJ sport 4.0L. Your list has a gap from the 2 o2 system to the 4 o2 system. Mine has a build date of 8/99 and only have 1 upstream and 1 downstream. The factory sensor P/N that has never failed is 56041676AA. Orielly’s shows to use NTC 23122, which you also show as B1S1. Do you think that is correct? I have to say the stealership wants $100+ for one, but I’ve never had a problem with it even after 18 years. I just wanted to replace it as I know they become less accurate with use and I just put in a set of rebuilt injectors in an effort to maximize mpg and reliability.

Side note: the 2000 is an odd duck. I’ve noticed not a single aftermarket exhaust company has a manifold or downpipe for this year. And if they do advertise it you can clearly see the design isn’t the same. I’ve thought about just changing everything over to a different year. I also have COP and a crank sensor instead of a distributor. And my charcoal canister is still under the hood.
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My mistake, that was a typo in my original post. I meant to say 1997-1999, but I wrote 1997-1998 on accident!

You have the exact same sensors as the 97-98 models as well, which are:

1997-1999
NGK #23151 - Bank 1, Sensor 1 (Upstream)
NGK #23099 - Bank 2, Sensor 2 (Downstream)

So yes, your part numbers you have are 100% correct.
 
Megalodon said:
Looking for the correct sensors for 2003 Wrangler Rubicon with error codes 0135 & 0155. Any help would be awesome!!
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The correct sensors for those codes are as follows:

NGK #23139 - Bank 1, Sensor 1 (Upstream)
NGK #23138 - Bank 2, Sensor 1 (Upstream)

If you click on those links, you'll also see that Amazon confirms that they do indeed fit your 2003 Rubicon.
 
The 23138 and 23139 I have received and currently soaking PB Blaster before attempting the removal. I didn't see a diagram of which one goes where, are the connectors the tell all or do they go into specific ports? I.E. front or rear.
 
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