This FLO - 20141 4" downpipe back exhaust system by FLO - PRO is a top - notch upgrade for your 2020 - 2023 GMC 6.6L Duramax with a 4 - bolt flange. It's designed to fit all wheelbase and cab configurations. Replace your stock components with this high - performance and high - flow 4" piping. You'll experience improved fuel mileage, increased torque, and a better - sounding 6.6L engine. Just like all Flo - Pro exhaust kits, it comes with all the necessary clamps, pre - weld contour bent hangers, and stronger flanges for an easy installation. It features a 4" down pipe back exhaust, an OEM style 4 - bolt flange, a high - flow muffler, and is available in aluminized or T409 stainless steel. Note that these kits only fit models with the OEM style 4 - bolt flange off the turbo direct pipe.

Using this exhaust system is simple. First, make sure your vehicle is a 2020 - 2023 GMC 6.6L Duramax with an OEM style 4 - bolt flange off the turbo direct pipe. Remove the stock exhaust components carefully. Then, install the new exhaust system using the provided clamps, hangers, and flanges. It's designed for easy installation, but if you're not confident, it's a good idea to get professional help. When it comes to maintenance, check the clamps regularly to make sure they're tight. If you choose the aluminized option, it might rust over time, so keep an eye on it. For the T409 stainless steel version, it's more resistant to corrosion. Clean the exhaust periodically to keep it looking good and functioning well. And remember, this system is made to improve your vehicle's performance, so enjoy the better fuel mileage and increased torque.