Ive become decent friends with my service manager and the guys up there. there are all diesel heads too. a guy rolled in with banks exhaust and banks chip. he has 30K on his f250 and cylinders 5 and 6 are out i think. Well, some guys showed up from ford last week and cancelled his warranty! my service manager said he didnt even know they where coming and had ne known he would have even told the guy to remove the chip first. Know the guy is getting a lawyer and etc..Turns out that the dealership that i take my truck too has alot of guys who trick up their f250s..Manager said it was a $10K fine for him changing his exhaust!