Originally posted by: exdeath
Yeah, Magnuson-Moss Warranty Act. Dealer cannot void warranty unless it can be shown that the modification directly attributed to premature failure. If you stick a supercharger on your Mustang GT and the horn stops working they can't legally deny warranty coverage on the horn. Similarly if your crank snaps in half or you throw a rod in the normal course of non abusive driving because the oil pump failed it's not because you stuck a K&N filter on it and legally you must be covered under warranty.
If you burned a hole in a piston because of a poorly programmed after market chip or because you tampered with the MAF meter and other evidence such as burned cats and O2 and spark plug deposits, etc suggests that your modifications resulted in a lean tune that caused the damage, that is NOT covered under warranty.