Can the dealer tell if the truck has been programed even if you return it back to stock before getting it serviced. Thanks for the help

They will never know if you put the stock program back and I doubt they would ever look to begin with.

Correct, they cannot tell once the stock program has been reinstalled. I tool my '05 in for a cosmetic problem, I asked the service writer, who also used to be a technician, about it. He said there is no way for them to see if the program has been changed in the past.

They don't care, well at least my dealership doesn't, as a matter of fact, they sell some with it already installed. I put mine in the cab and thay take it off if they have too.