The Official Jeep Wrangler TJ Oxygen (O2) Sensor Thread
- Thread starter Chris
- Start date
No experience with them. The main problem I had was the cat fitting with the manifold, if the welds are off just a little you have a hell of an exhaust leak, you can check the angles and make sure that they match.
So I have all 4 sensors for a 2005 LJ and can't tell whether they are M12 or M18 sensors to know what torque spec to use.
I know this is a strange request but could somebody with an 05/06 (or TJ with the 2 Cat, 4 O2 sensor system) send me a picture of where the the quick connect electrical connector is located for bank 2 sensor 1?
I just replaced my core plugs and after putting everything back together I cannot find the connector from the ECU. On my wire harness I think there looks to be loose tape in the spot I believe the connector should be originating from.
Thanks in advance for any help.
I just replaced my core plugs and after putting everything back together I cannot find the connector from the ECU. On my wire harness I think there looks to be loose tape in the spot I believe the connector should be originating from.
Thanks in advance for any help.
The other one that might be getting you is cyl 3-6 after cat. It’s on top of the trans, can’t see it just have to believe.
When I changed my cat a few days ago I pulled the old O2 sensors and left them hanging from their plugs so I could find them again because I had seen how funky those locations were.
I changed the CAT out like 4-5 times, finally got a not DOA part last weekend. Got it down to like 1/2 an hour to swap them. Once you know where they are I found it easier to unplug the bottom ones and take them out with the CAT, then swap them over and re-install. that bank 2 sensor 2 plug is a real PITA though.When I changed my cat a few days ago I pulled the old O2 sensors and left them hanging from their plugs so I could find them again because I had seen how funky those locations were.
Hi Chris,
I'm just reading through the O2 chapter in the service manual (2003 TJ) and found this:
"INSTALLATION Threads of new oxygen sensors are factory coated with anti-seize compound to aid in removal. DO NOT add any additional anti-seize compound to the threads of a new oxygen sensor" see pp 1104 ff.
Maybe you should mention that in your installation notes; I'm not sure if your advice still applies to other models?
Andy
I found the manual on this page: https://wranglertjforum.com/threads...ice-manuals-fsm-technical-documentation.4618/
OP
Interesting, none of the O2 sensors I’ve replaced ever seemed like they had anti-seize on them, but maybe it was just a super thin coat? Either way, good suggestion.
That's one of your links, just Australia: https://www.amazon.com.au/dp/B001PNCNF6/
When you zoom over the image you'll see some kind of grease on the thread but no text mentioning it.
Plenty of do nots here: https://www.ngk.com/learning-center/article/328/oe-identical-oxygen-sensors-installation-inst
There is a comment on this page: https://www.amazon.com/dp/B001PN8UEO/?tag=wranglerorg-20
"Jonathan Campbell
5.0 out of 5 stars This fit perfectly in my 2003 Jeep Wrangler X (4 ...
Reviewed in the United States on May 10, 2015
Verified Purchase
This fit perfectly in my 2003 Jeep Wrangler X (4.0 I6), even came with anti-seize on the threads already. There are (4) O2 sensors and this one is for the downstream (after the catalytic converter). It's the sensor towards the front (shorter wire). If you need the downstream O2 sensor towards the rear you want the NGK 23141 (longer wire)."
I guess the manual is right (at least for genuine parts) and there is anti-seize on it already.
OK, that's the one: https://ngksparkplugs.com/en/resources/oxygen-sensor-installation
Anti seize comes either already applied or is enclosed: "If not already coated, apply (enclosed) anti-seize to oxygen sensor threads."
When you zoom over the image you'll see some kind of grease on the thread but no text mentioning it.
Plenty of do nots here: https://www.ngk.com/learning-center/article/328/oe-identical-oxygen-sensors-installation-inst
There is a comment on this page: https://www.amazon.com/dp/B001PN8UEO/?tag=wranglerorg-20
"Jonathan Campbell
5.0 out of 5 stars This fit perfectly in my 2003 Jeep Wrangler X (4 ...
Reviewed in the United States on May 10, 2015
Verified Purchase
This fit perfectly in my 2003 Jeep Wrangler X (4.0 I6), even came with anti-seize on the threads already. There are (4) O2 sensors and this one is for the downstream (after the catalytic converter). It's the sensor towards the front (shorter wire). If you need the downstream O2 sensor towards the rear you want the NGK 23141 (longer wire)."
I guess the manual is right (at least for genuine parts) and there is anti-seize on it already.
OK, that's the one: https://ngksparkplugs.com/en/resources/oxygen-sensor-installation
Anti seize comes either already applied or is enclosed: "If not already coated, apply (enclosed) anti-seize to oxygen sensor threads."
Last edited:
The NTK sensors I just installed did have a small amount. Here's the thread cap from one with some still on there.
OP
I guess I will find out shortly since I am due to change mine with the ARH header install.
This O2 sensor topic is obviously much more difficult than I thought. I did have a chat to my mechanic yesterday and he told me that one sensor costs about 300 AUD. An insane price tag if you ask me. I did send him those amazon links (the sensors are about 55 bucks here) and he responded:
"Anywhere you go and ask for oxygen sensor is around that price. Some cars can go up to $400! So I'm telling you the price you found is wrong."
Allegedly these NGK oxygen sensors are OEM parts (I found that somewhere here on this forum) but the service manual and the parts list don't mention any brand name.
Does anyone know where that information came from?
Could it be that the offers on the amazon page are cheap Chinese knock-offs?
Or are there any differences in those sensors that allow for a 10 times price difference?
"Anywhere you go and ask for oxygen sensor is around that price. Some cars can go up to $400! So I'm telling you the price you found is wrong."
Allegedly these NGK oxygen sensors are OEM parts (I found that somewhere here on this forum) but the service manual and the parts list don't mention any brand name.
Does anyone know where that information came from?
Could it be that the offers on the amazon page are cheap Chinese knock-offs?
Or are there any differences in those sensors that allow for a 10 times price difference?
It sounds like he's full of shit. I got all 4 for ~ $100 USD.
That sounds about right. A bit more than in the US but within reason.
Quick question... Can my '98 2.5 TJ use NGK 23506 or do I have to use the "1998 ONLY" NGK #23151 ?
4 Cylinder Engines
1997-2000
NGK #23506 - Bank 1, Sensor 1 (Upstream)
NGK #23151 - Bank 1, Sensor 1 (Upstream) (1998 ONLY)
Looks like the 1998, the sensor itself might be the same, but the 98’ version has a much longer plug. so if you get the generic it’ll thread in fine, but then you can’t plug it in
Must be due to the exhaust on the pre 2000’s. Didn’t y’all have some weird like 6 into 1 precat?
Ahhhh... longer plug. Thanks for the heads up.Looks like the 1998, the sensor itself might be the same, but the 98’ version has a much longer plug. so if you get the generic it’ll thread in fine, but then you can’t plug it in
Must be due to the exhaust on the pre 2000’s. Didn’t y’all have some weird like 6 into 1 precat?
MrMark52
TJ Enthusiast
Just a thought - if 23506 is horribly expensive relative to the 23151, splice the wires from the old sensor to extend the new sensor.
This of course assuming the sensors themselves are the same (I’ve not studied O2 sensor technology enough to know, or have forgotten anything I may have known at one time).
This of course assuming the sensors themselves are the same (I’ve not studied O2 sensor technology enough to know, or have forgotten anything I may have known at one time).
Good idea, though I have no clue if there the same or not, assume they are. The only difference I could tell was the pigtail length, much like on the 01 4.0 that I have. Doesn’t matter up or downstream matter how king the tail is. (I think it’s the 1:1 and the 2:2 that are the same length but I would have to go look)