I bought a 2003 envoy last year with 100,000 miles on it. fully loaded. paid 5400 for it. fully loaded. haven't had a single problem wiht it except the air bags leaking and i replaced them and solved that problem. i did the 100,000 mile plug change and just regular oil changes. i put a k&n air filter in it. i know i need to get the tranny oil flushed, and change all the fluids since i don't know the history, but anyways, just started getting a rough idle tonight only with a/c compressor on, and it is not really a rough idle. just cuts out at idle like it is going to die and comes back up to normal idle. no codes, no lacking of power on takeoff, just get the cut off idle with compressor on. what could be problem? i am thinking maybe dirty throttle body and/or clogged fuel filter? i checked throttle body when i did spark plug change but it didn't look that dirty.