Description
Overview
The Flowmaster American Thunder Cat-back Exhaust System is engineered for 2009-2021 Toyota Tundra trucks equipped with the 4.6L, 4.7L, or 5.7L engine. Built for the driver who wants a deep, aggressive exterior tone paired with a mellow growl inside the cab, this system delivers the performance benefits you expect from Flowmaster while transforming how your Tundra sounds and breathes. It’s a true bolt-on upgrade designed for at-home installation, backed by American Thunder engineering.
At the heart of the system is a specially designed dual-inlet Super 40 Series muffler with a 2.50-inch inlet diameter, flowing into dual 2.50-inch mandrel-bent tailpipes. The mandrel bends preserve smooth flow for maximum performance, while the Super 40 muffler gives the American Thunder its signature aggressive character. Every component features all stainless steel construction for lasting durability, and the tailpipes are capped with a pair of 3.50-inch double-wall polished stainless steel tips for a clean, finished look.
Two Exit Configurations Included
The kit ships with two complete sets of final pipes, so you can tailor the exhaust exit to your truck and driving style. Choose the dual-out-the-back layout for a bold, traditional look, or install the dual-out-behind-the-rear-tires configuration, which is especially beneficial when towing. Everything needed to complete the job comes in the box, including all necessary parts and hardware.
Key Highlights
- All stainless steel construction for corrosion resistance and long service life
- Dual-inlet Super 40 Series muffler with a 2.50-inch inlet for an aggressive tone
- Dual 2.50-inch mandrel-bent tailpipes for maximum flow and performance
- Two sets of final pipes: dual-out-the-back or dual-out-behind-the-rear-tires (great for towing)
- Pair of 3.50-inch double-wall polished stainless steel tips
- CARB (California) compliant and emissions-legal with all mounting hardware included
Sound & Performance
Flowmaster tuned this system to produce a deep, aggressive exterior note while keeping interior drone in check with a mellow growl inside the truck. The result is an exhaust that announces itself outside without overwhelming the cabin on long hauls, making it equally at home on the daily commute or the job site.
Fitment
This cat-back system fits 2009-2021 Toyota Tundra trucks with the 4.6L, 4.7L, or 5.7L engine in both 2-wheel and 4-wheel drive applications. Please note: it does not fit regular cab/short bed or double cab/long bed models, and 2009 models must be built after 08/2008. No heat shield is included. This product carries a California Proposition 65 warning. Confirm your cab, bed, and build date before ordering to ensure a proper bolt-on fit.










