stlwagon is right, when we hook a scan tool up to a car that has been programed b4, we cant tell anything..........if you return the car to "stock" trim right b4 you bring it in, it WILL tell us that the car has not completed a full drive cycle that it needs to do to check if everything is functioning properly (the car scans 02 sensors, etc, etc).......but we cannot void your warranty solely on that, because heck, you might have just had the battery unhooked...........the CAI will not void your warranty as long the part that breaks is not directly related to the intake. (if you come in with your air/fuel ratio screwed up, no warranty).......there are exceptions to all of this said, so if you own another vehicle, dont think i cant prove a chip was in it......the new diesel will tell me straight up if it had one. But a stang', dont worry about it!!! lol