I just put a 2 chamber flowmaster on my 07 nbs silverado with turndowns just before the axle. The problem is when 4 of the cylinders shut down to save gas which is every damn ass 2 seconds it sounds annoying as hell. Is there anyway you can do away with that. If not I'm gonna have to go back with my stock muffler. It's sounds good one minute and like a big block harley with a exhaust leak the next.