This Flowmaster Flow FX cat-back exhaust system for the 2020-2025 GM 2500HD/3500HD trucks with the 6.6-liter gas engine is manufactured using durable 409 stainless steel throughout and features 3.50 to dual 3.00-inch mandrel bent pipes for better exhaust gas flow, and a Flow FX straight-through muffler is used for a moderate sound level and maximum performance. Maximum increases on the dyno revealed +9 hp and +10 lb-ft at the rear wheels.

This system exits out both sides, behind the rear wheels with 4.50-inch black ceramic tips for added style and a custom look. The system uses all the existing factory hanger locations and includes installation instructions and all necessary hardware for an easy installation that you can do at home. Backed by Flowmaster's Lifetime Limited Warranty.

• Max increases of up to 9 hp and 10 lb-ft over the stock exhaust at the rear wheels
• 3.50 to dual 3.00-inch mandrel bent 16-gauge 409 stainless steel tubing maximizes exhaust flow and improves durability
• 4.50-Inch black ceramic coated tips add a custom look to the truck
• Includes complete hardware and factory styled hangers in the stock locations for an easy installation
• FlowFX “straight through” performance muffler delivers a deep, aggressive to moderate performance tone and improves exhaust flow