O2 sensor or emission problem??

Guys,

I have a 1996 JGC 4.0 I6.

I'm struggling with this one. I've had a rough idle problem that I have lived with for a while because it is only inconvenient. After looking hard at plugs, wires, coil, IAC and all of the obvious things that could be causing it, I just let it ride. I've even cleaned the throttle body and decarb'd with Seafoam to no avail.

Now, the problem is that on occasion, when I come to a stop, the TAC will go down to almost zero, the battery voltage decreases and it almost completely stalls, but never quite cuts out. In fact, if I place it in neutral, it recovers, but just idles rough and I get a very tiny hesitation when I give it gas again (but again, not enough to stall).

The kicker is that I do smell exhaust during the most extreme cases when the Jeep almost stalls out. This leads me to believe that maybe I have an issue with an O2 sensor that is flaky, but not enough to start throwing codes.

Having never changed one before, (mine has two) is it pretty easy to take them off and maybe decarb them a little to see if this helps or should I just go ahead and replace them if I have never done it before. I replaced the CAT converter a while back during the recall. I had a muffler shop do it, so it is not a Jeep part.

Any thoughts???

Thanks guys,

Bryan

Does you Jeep have problems with oil getting into the air filter? If so, both your Jeep's CCV breather system and MAP sensor are suspect. If there is oil in the air filter, you need to clean or replace both.

Just my :2cents:

sure sounds like the same problem I had. It was the Throttle Position Sensor.

I thought I would post this again. Anyone got any thoughts here??

Thanks

I replaced the O2 sensor in my '94 Jeep GC. I can't remember why - whether it was throwing codes or just performing poorly. Either way, it was pretty easy to replace. I just have one on my model (before the CAT). I was able to unplug it, remove it with a crescent wrench (give it a good bump to break it loose), and screw the new one in. I don't recommend fussing with cleaning it because (although it might temporarily improve things) if the problem persists you won't be sure whether it's a bad sensor or something else. It's not too expensive to replace them yourself. Let us know if you have questions or if the new sensors make an improvement.

I'm having almost the exact problem with my 98 JGC. My check engine light is on and the code reads "bad o2 sensor" but says its ok to drive. Just bought the car a week ago and the light was not on until 2 days ago. I cant get an inspection sticker with this problem. How much is this to replace..and should the dealer pay for it? Sometimes it runs perfect...and sometimes it chugs and hesitates. got a great deal on the car and just want it to run right. any help??

Ignition coil...

also sounds like thew starts of a fuel pump like it is getting weak that is how gf jeep started and now it won't crank because the pump went out got it replaced today and it cranked and runs great but now my fuel gauge don't work