2001-2004.5 Duramax 4" Cat Back Exhaust System w / Muffler (431108 / 432119)

Flo-Pro Exhausts are designed to fit all wheelbase & cab configurations unless otherwise specified.

The 431108 & 432119 by Flo-Pro is a 4" Cat-Back exhaust system for the 2001-2005 GM trucks with the 6.6L Duramax. This system replaces your restrictive OE exhaust with a 4" high-flow system with an in-line muffler from the catalytic converter back. Just like all of Flo-Pro Manufacturings Exhaust kits, it will come with all the required clamps, pre-weld contour bent hangers, and stronger flanges to help you sail through the installation process. It not only sounds better but it will also improve your torque, throttle response, and mileage!

Part Number: 431108 & 432119

• 4" Cat-Back Single Exhaust system.
• Includes Muffler
• Retains Cat For Emissions
• Aluminized Steel & Stainless Steel Options
• Single Side Exit
• Easy Install - Mounts to OE Hangers

Aluminized steel is the budget-friendly choice. It has a protective coating that holds up well, but once that coating wears it will eventually rust through, especially in salted winter climates. The stainless option is T409 stainless, an automotive-grade steel built to resist rot, and it will typically outlast the truck. T409 is not polished show-grade stainless, so light surface rust or discoloration can still show up over time. That is cosmetic only and won't affect performance or service life.

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