I just got a 99 XJ. The 02 sensor behind the cat had the wires ripped out when I got it. I bought a new one replaced it, zip tied it away from the drive shaft. After I replaced it with new one it was running strange. Then I decided to check the fuse under the hood, sure as **** it was blown. Replaced the fuse, check engine light went off. Drove it for a day and check engine light came back on. Put a scanner on it and the coad read hi voltage on the rear 02 sensor and also said mechanical malfunction in the torch converter. So I checked the fuse again to make sure I wasn't having a bad wire issue and the fuse was good. It no longer runs strange and the tranny is shifting fine, everything seems fine. Anyone have any info on this topic??

 

Damage to the wiring harness causes that. Look further up, the tranny wires are in the same bundle as the rear O2 along the passenger side.

 

Which O2 sensor did you use, universal or stock replacement? Universal ones from my experience can sometimes set the CEL if the connections are not true.

 

Thanx I will look further up the harness for damage. I did replace it with a stock Bosh replacement. Like I said it is running perfectly fine, but where I live here in NE Ohio every year I'm required to take an emissions test. If the check engine light is on they will not test it and I can not renew the sticker on my plate. I still have a full year till I have to take that test again.

 

NTK is the OE for every XJ made after 1990. I don't see a Bosch causing CELs but they definitely do not perform like NTKs in the Chrysler years.