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Hello... I have a 97 TJ with a 2.5l with 180K plus miles. Recently I've been hunting a misfire issue that I thought I had fixed. It started a few months ago with a misfire/sputter when accelerating. I changed out the throttle position sensor and it was like a new Jeep. I've never had overdrive before and suddenly it was a rocket while accelerating. Then last week it suddenly started having an issue when I slowed down to a stop light or pulled into a parking spot, the Jeep would suddenly die. It seems to happen when the Jeep rocks forward or from side to side. BUT again, only happens after it's been running for a while! I've cleaned the throttle body and I'm waiting on a new Idle Control Valve to be delivered (not a single store had one in stock!).



In the meantime, I've consulted with a bunch of Jeep-buddies and they suggested I do a wiggle test on the wiring under the hood while it's running. I started tugging on wires today and pulled this loose from somewhere and I DON'T know where it goes. It looks like it was pretty corroded and it has a circular type connector. It goes up to the wiring harness that runs along the length of the firewall but I can't find a diagram anywhere online. Thanks in advance!



https://ibb.co/Xj1S4js
https://ibb.co/qrWgkFb
https://ibb.co/7C1mtZz
https://ibb.co/TTMtN4h
https://ibb.co/t3RbfWf
 

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Since you say the problem only occurs after the engine has been running a while, does that mean it runs fine when cold? If so that's a pretty good sign the upstream O2 sensor has gone bad. The computer only looks at the O2 sensor data after the engine has started to warm up. And it's only the upstream O2 sensor that will cause that kind of problem, the downstream O2 sensor only checks the catalytic converter for proper operation.
The upstream O2 sensor is what the computer uses to set the air/fuel mixture.

If you decide to replace the upstream O2 sensor, make sure to only use an NTK or NGK which is the OEM. Don't use a Bosch, they don't work well for long in our Wranglers.

That unused connector in the first two photos is for a hood light which was an option for all TJs.
 

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Do you still a hood mounted engine bay light? Is it connected? That may be the wire for that.
 
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