I have a 2006 gt, the only mod was the other owner changed the exhaust, I'm not sure what exhaust. Anyway...I have an 07 Expedition that I put on Magnaflow exhaust(which sounds awesome) then put in a K&N CAI, every once in a while the car seems to sputter a little under acceleration, so now I'm leary to put the CAI on the Mustang. Does anyone else have this problem with their cold air intake?