I have just bought a 2004.5 2500HD for my wife at a auction and have no history of the vehicle so I dont know if it has a programmer/chip on it but it runs almost as well as my other 2004.5 dmax with juice/***. on #3. I am wondering if there is a way that you can tell if anything has been done??? thanks for the help.

hmm, the edge would be obvious under the hood, but if its been programmed then they should have included the programmer because it can't be used on anything else while its being used to program a vehicle. only way I would guess is to stop by the dealer to see if their scanner can read it or not.