Before and after clips of a 2001 Silverado 2500 LB7 Duramax. The exhaust is a cat back MBRP 4 inch system with a muffler. The truck also has a S&B intake and a Hypertech Power Programmer 3. The videos includes both interior and exterior views showing the sound of the startup, idle, revving, and various driving. Sorry for the buzzing sound in the interior when the truck idles with the new exhaust. MBRP part #S6000AL.