I don't know, I'm just not feeling it with those mufflers. Not sure if it's the cats, or x-pipes, or mufflers (or lack of), firing order, but it's a rare set of mufflers on a C5,C6,C7 (so far) where I really like the sound. They all sort of sound..not sure how to say it, fuzzy, or mumbley, at idle and it just doesn't say "I'm going to rip your head off!" when even at idle like some of the old iron does. I don't like loud for the sake of loud, I like good, and if it's good, then make it loud. Maybe nothing stock does that until you throw a cam in it. Not too sure..... Maybe I'm just whining today?