Ok so i have been having trouble trying to figure out my idle shake. I have posted on so many threads what to do. Though everything that i have tried has made no diffrence. cap,rotor,cables,plugs,iac,tps,seafoam,fuel pressure test,fuel filter,clean throttle body, motor mounts. Still nothing. No codes, drives fine when you hit the gas. I have had other guys with jeeps take a look to see if i was crzy and they say the same thing that there is a slight miss. So today i tried to unplug the map sensor by the throttle body, while the jeep was running, it really did not seem to make a diffrence though when i went back into the cab the check engine light came on!! I plugged it back in though still check engine light? So my question is this. Could it be the map sensor that is causing the rough idle. Also should the check engine light come on for the map sensor. :doh: