Hello everyone! I have been experiencing the same problems most of the Chrysler Jeep owners experience. Intermittent stalling, rpm drop, rpm fluctuation, possible backfire or misfire. I have had the following significant parts replaced: spark plugs (without the wires), distributor, cam sensor, crank sensor, fuel filter, coolant temp sensor, and IAC valve. I do have a check engine light on with the code P0420 but the symptoms were long there before the code popped up. I have taken my Jeep to 5 mechanics and even the Chrysler dealership and not one of them can tell me anything. With the code being a P0420, my personal mechanic (who is an actual mechanic) says that 9 out of 10 times they would go an replace the converter and o2 sensors. He actually drove the car around and experienced the stalling and bucking (usually at low speeds). He never felt anything at freeway speeds but i've had the cars rpm drop to about 1000-1500rpm when I'm building acceleration and cannot get above the desired speed (this rpm drop only stays down for 5 seconds and then kicks back to normal). I then will be able to drive the whole 20mins home without any problem. Back to the P0420 code, my mechanic knows it's there but experiencing the problem firsthand, he does not think that a catalytic converter would do that. He says that a converter is either working or not, and the problem/symptoms would be there all the time instead of the intermittent problems I've been experiencing. After he replaced the distributor, the car ran fine for one week, which is a long time, considering it used to happen all the time. I am just now starting to experience the problems that were there before the distributor was replaced, and it seems as if it is getting worse everyday. I am convinced that there may be a short somewhere and a wire not getting enough volt to suffice. I think the next step would be to replace the pcm, and if that doesn't work the wiring harness - but I would never waste the time or money on that. My whole fame drives Chrysler and have been having problems, so I may have to buy foreign since they do have the best reliability around these days. Who do you guys think? - I'd appreciate any personal experience or advice on this unsolvable issue that seems to have Jeep owners stumped.

 

Fuel Pump! I am willing to bet 5 bucks on that. You can get a kit for 50$ off eBay. Takes a good afternoon to replace. How I know you ask. I have had the same problem.

Plug in the computer. Does it talk about the system being to lean?

If not that i would check the cat....

See, When I had this problem I could not get the car going at very low speeds and it would kinda take it a while. If it did not stall. But once I got the thing up past 40 you could not tell anything is wrong.

 

Change the plug wires and see if there is any change, check the fuel pressure.

 

Thank you guys for the the replies. I will check out the kit on ebay for sure, but before that I'll go ahead an change the wires. My mechanic said that the fuel pressure is good. I'll post again if any of your suggestions do the job, but since I've been dealing with this for so long it's like I have no expectations, you know? - usually when something is too good to be true, like finding a simple fix, it usually is...lol - but ill my best to continue to work on achieving the answer for so many other Jeep owners dealing with this same problem. Please, anyone feel free to continue commenting on this thread.

 

Check your grounds and check to see if your exhaust manifold is cracked,sometimes if that is cracked it will screw with the idle.Also check inside the distrbutor I think the guts are called a hall effect pickup that will cause a stall every so often,unless it is a brand new dis then nevermind (I see you swapped the dis didnt know if it is brand new or used) these are just suggustions hope it helps.

 

this codes generated when your post o2 sensor reads similar values to your pre cat o2 sensor. this can be really related to catalytic converter or just a crack on sensor mount. once i had a cracked post sensor with a lost tip.

stalling and hunting idle is something different, this is related to pre o2 sensor or mass air flow meter( if any) or absolute pressure sensor.

i faced this one too, car is ok when it engine is cold and it gets worse when it siwarmed up. performance is degraded and it consumes two time more.