[CWD98TJ]

Jeep runs fine for about 5 minutes. After 5 minutes idle will speed up and down to about 500rpm very inconsistent. After it's hot it will sputter at cruising speed almost like its choked and still idle inconsistent. Also gas mileage is poor

[Pillswoj]

I assume it is not throwing any codes? I would suspect the upper O2 sensor as it is used to control the mixture only once the Jeep has warmed up. Try unplugging it, the jeep will then stay in default mode, if it runs fine then the sensor is your problem. With it unplugged your gas milage will stay poor.

[CWD98TJ]

Check engine light is not on. Where do i find upper O2 sensor

[Pillswoj]

It will be on the drivers side just below the exhaust manifold, on the headpipe of the exhaust. It is easier to reach if you crawl under the jeep.

[CWD98TJ]

I'll try this, will let you know how it goes

[CWD98TJ]

well this didn't seem to do it. anybody have any answers?

[CWD98TJ]

Cleaned TB after that Check engine light came on. Scanned out TPS and o2 sensor also fuel level sensor or something like that. Replaced TPS jeep runs alot better after a couple miles check engine light came back on. Time to replace o2 sensor it's going to take some work getting it out. I hope o2 sensor takes care of my lights coming on.

[PJL]

Have you checked for a vacuum leak? Those can cause those symptoms as well. Actually, I just had my rig in the shop for the same problem. They thought it was the computer, but after replacing the computer, it still had symptoms which turned out was a short in the clock spring mechanism. The problems started after I left it out in the rain all night. And if your idle's running rough, also check your idle control motor.

[CWD98TJ]

Idle is good now, once and awhile a littlte high but if o2 sensor is bad i would think it would cause this. O2 sensor controlls fuel mixture?????? Tell me more about clock spring mechanism. Scan called out o2 sensor so it should probably be replaced, right? Where should i check for vacuum leck?