Okay, I understang completelly now. I was under the impression that the PCM(Tune) would take care of the detonation. What is the point of getting a PCM if it is not going to be any good (waste of money, from what I get). I figure if you get a PCM it should be tuned for the mods you have. Why waste the money if it isnt going to help. I understand about the scanner tool, it would be a safe bet.