So I just installed my power pup level one on my LLY and I went to drive it. The engine was cold and it was a lot louder than any other time when I drove the truck cold. Is this normal? Once the engine hits 180 degrees the truck quiets down to how it used to sound. Also is it bad for the motor?

Mine does the same.....don't know if its bad per se....I beleive it is the timing clatter everbody talks about. However, I am not running the pup right now because the weather is turning colder...I put it in to play on days when it warms up in the afternoon.