Have any of you ever heard that the PCM can revert itself back to it's original factory stock tune on it's own? A friend of mine whose buddy works at GM was telling him that the PCM's are designed to let you think that you've changed the tune but will revert back to the original stock tune on their own. I'm having a hard time believing this and think it's just his way of discouraging people from doing anything to the PCM (towing the party line). Anyone have some feedback?