First off Ill start with mods. My 03 GT has pro m cold air intake and MAF, BBK shorty headers and catless pro chamber exhaust. Everything else is stock. Now to the issue. Since I bought it it has had idle issues. Starts up great and runs strong when warming up. But once warmed up you begin to see the idle drop. The average idle I see is around 600rpm( pretty low I believe). Some times when sitting there it will flutter and drop to 200 rpm then shoot to 900 rpm. Other times it will die out. Coming off the highway and engaging the clutch some times it will die out also. It's beginning to bug the crap out of me not being able to find out what's wrong. So far I have pulled intake off cleaned and recharged it. Ran it for a few hundred then went and cleaned MAF with proper MAF cleaner and throttle body. Cleaned throttle body thoroughly when I pulled it off to put in a new intake manifold. Problem still occurred so I replaced TPS and IAC with OE replacement parts. I also bought a brand new alternator off AmericanMuscle.com because I was informed low voltage could cause idling issues.Problem is still occurring. Idle jumps bad when AC compressor is on. Does anyone else experience this sudden die out and surging? Any suggestions? Looking at getting a new cold air intake and going to replace the MAF but can't find any good cold air kits including the MAF. Any suggestions? I do not know if the previous owner had it tuned or not. Could this be issues with the computer? Looking for any help this beginning to drive me crazy not being able to track this issue down.