My truck at certain speeds or when you let off the gas is making a light histing sound like a little air leak tick on the left hand side of the motor if you are sitting in the drivers seats. I have headers on the truck. The midpipes were just installed and there are brand new gaskets there so i know its not that. Any chance that the header bolts are loose? I hear this is a common issue and the headers have been on there awhile Idk if they were supposed to be retightened.
Bob
Bob