alright guys, for a while my jeep has had an intermittent low idle. occasionally when coming to a stop the engine will run around 3-500 rpms for a couple of seconds and then return to idle, sometimes even stall out. it almost always occurs when im on the trails in 4low and have been running around 2500rpms for a couple of minutes.... recent repair history- i have removed the throttle body, cleaned all the sensors including the iac, has a new tps, new psarkplugs, cap and rotor, ecm connectors have been checked and dielectric grease applied. then engine runs fine otherwise and no codes in ecm. i am thinking either a faulty ecm or bad iac? also jeep has a good battery and new alternator.

thannks for the help!!!

 

Try replacing the iac. I cleaned mine and it didn't work that well so I replaced it and boom my idle is at about 700-800 rpm