Hey guys i have a 95 cherokee with a 4.0 and since i've had it, about 6 months, sometimes when i go out to crank it in the mornings it cranks and runs fine and everything but after a few minutes its starts to idle real low and right before it wants to cut off it idles up to about 1000-1200 rpm. It does it a few times then it quits. Also sometimes when i go to take off like from a stop it kinda sputters and doesnt want to accelerate then it seems like it backfires through the intake then it takes off and runs fine. It only seems to do it between 1500-2000 rpm. I dont know what it could be because it only does it sometimes. And also the check engine light comes on just about every time i drive it but it comes on at different times, like sometimes as soon as i crank it and sometimes after it gets up to temp. What suggestions do yall have?

 

upstream o2 sensor! thats what mine needed and i had the same problem

 

My suggestion is take it to your local auto parts store and pull the code! That'll give you the best idea of what's going on. The upstream o2 is definitely suspect though

 

What computer code are you getting? They are easy to check on a '95 using the key on-off-on-off-on method.

 

I used an old otc code reader a while back to read the code and it was some kind of lean code but i can't remember exactly what it was. But i'll probably try replacing the o2 sensor and see what happens.

 

Yeah that sounds like the o2,just remember it might not always throw a code

 

I had the same issue. I replaced 3 things, but only because they are cheap (to me) I replaced both O2 sensors and my IAC (it was rusty - no lie) Cleared the codes, and it runs great AND my misfire at idle is even gone. Got all the parts at Rockauto.com just a hair over $100.00

 

Before throwing money at it, get the code read. Autozone will do it for free. Not sure about the other auto parts stores but I'm assuming they probably will too

 

Def. sounds like the pre-cat o2. Had the same problem with mine after I got it. Easy fix though.

 

Well i replaced the o2 sensor yesterday and everything seems to be fine now. No codes, no sputters or anything. Thanks for the help guys

 

glad to hear it, thanks for the update....