04` missing at idle?? plz help!
 

Hi all! Have an 04` with 4.0. Have read the posts on missing at idle & have done MOST of what was there (except comp. check) Cant seem to find the valve on this thing to check fuel psi?? any ideas? Runs great driving but misses & knocks some at idle, & puffs alot of white smoke when ya romp on it. Possible cat?:(

check engine light? codes? Inspection for carbon tracking on the plugs/coil boots?