Bear with me cause I'm a bit confused. Why would a battery or starter cause me to have idle problems?

 

Basically everthing is controlled electrically. For instance if your not getting proper voltages to ignition or fuel suppy components they won't function properly.

 

The battery is only for starting the vehicle, the alternator is what keeps the electronics going. That's what my understanding has always been. I don't think it's going to be either one of those since I'm not having any problems starting it. Thanks for the help though.

 

Mine will struggle occasionally when I first start it up for i'd say 30 yards then runs fine.
I know for sure I need to tune mine up and probably need my 2nd o2 replaced.

 

I wouldn't think so as long as your alternator is working

 

+1

"the alternator is what keeps the electronics going."

Yep. And if it's not.....................

You need to have your OBDII checked for codes so get everything else I listed checked to. For one it's free and two then you'll know for sure that all is up to snuff.

 

didn't notice before that you had can 01. unlike my 99, you do have coil packs, and they can cause issues like this. as for the CEL, it doesn't always come on if theres an issue. I've been through this with mine and its worth 30 seconds on the scan tool. the other thing id highly recommend doing is to have a good diagnostics machine plugged in while its running so you can monitor the functions of all your sensors. this is how we confirmed the o2 sensor on mine was reading a little outside its normal range. if it doesn't clear up under WOT, then its probably not the o2.. id say check the coil packs but do the cheap/free stuff first. oh and if there is an issue with the alternator, you can always test it with a voltmeter, but, if after ~10 main of running your alt. is hot, then theres probably something wrong.. easy test..

 

Well the engine just threw two codes today. It's a bad O2 sensor, bank 1 sensor 1. The other code is bank 1 too rich. I'm really hoping when I replace it, I won't have anymore problems. Thanks for all the responses. I have an auto diagnostic tool at work, I just didn't think it would tell me anything was wrong if the CEL wasn't on.

 

glad you were able to pull info from it to get a more specific diagnosis. always nice to know if your on the right path. its a weird system that simply stores info without informing you.. too bad it doesn't blink when you turn on your jeep to let you know theres a code stored. ifs and buts at this point.. hope it works!

 

I had a similar problem in my 4.0 tj and it ended up being the TPS. I would also check for a clogged fuel filter, ethanol is a b****

 

The code indicates the problem, you're running rich, the code does not neccessarily mean the sensor is the problem, it's doing its job.

If you look up the diagnostic touble shooting for the code, one of the last things on the list to replace would be th o2.

Typically if it were the o2, it would say lean condition as it's al carboned up and cant read the exhaust stream.

 

The first code said it was the O2 sensor high voltage on bank 1 sensor 1. Idk, it seems like I fix one thing, just so something else can break...I have horrible luck lol.

 

that can be summed up by saying its a jeep. it does that. just an excuse to upgrade most of the time.

 

haha true!

 

Just remember: fault codes identify the problem CIRCUIT, not a "problem sensor" (usually, faulty wiring is more likely).

Have you pulled the plugs? Are they sooty to confirm the rich condition? Is one or more different than the others that may look normal to indicate a leaky injector?