Shop Aftermarket Exhaust Systems and upgrade your 2011-2016 Chevy/GMC 6.6L LML Duramax. As soon as you begin looking for an exhaust, you will see a variety of construction choices and price points. Exhaust systems can be constructed in either stainless steel or aluminized steel and are available from many manufacturers. A performance exhaust kit will typically add horsepower/torque, decrease the exhaust gas temperatures (EGT's), and can even help engine efficiency. Different diameter exhausts are available such as 4" & 5" and offer unique sounds for your vehicle. Exhaust installation is normally a do-it-yourself project that can be completed in your driveway. You can find exhaust systems from all of the leading brands like MBRP, Magnaflow, AFE, Banks Power, AP Emission Technologies, and more!