I just bought this car, it's a 03 gt with crower stage 2 cams, long tubes, h-pipe, catback, and a jlt ram air intake. Everything else is stock, I'm having basically like a stumble while driving, sometimes it does it under a load other times it does it while at cruise. There's no CEL or anything, I took it to the local stang specialist and he put it on the computer and said it was a bad MAF, I went ahead and had them change the fuel filter and do an inj, tb/intake, and IAC cleaning. I got a new MAF from ford changed that and it didn't fix it, I've checked for vaccum leaks and all that already and found nothing. The guy I got the car from had it tuned but put the headers on after it was tuned, it's running a little rich, if u stand behind it it will get u high. If I let it idle in the garage too long it will burn your eyes. I'm begining to think it's the tune but there's no tuners in my area...anyone else have any idea what else I could check before getting it retuned??