Description
Overview
The Flowmaster American Thunder® cat-back exhaust system is engineered for the 2004-2008 Ford F-150 and Lincoln Mark LT equipped with the 4.6L or 5.4L engine. It’s the ideal upgrade for truck owners who want a deep, aggressive exterior sound paired with a moderate interior tone, backed by the performance benefits Flowmaster is known for. This is a complete bolt-on kit that delivers a serious attitude without the drone, transforming both the sound and the presence of your F-150 or Mark LT.
At the heart of the system is a specially designed Super 40™ Series performance muffler, feeding dual 2.50-inch aluminized steel tailpipes. The entire system is built from 16-gauge mandrel-bent aluminized steel tubing with a 3.00-inch inlet, so exhaust flows freely from the muffler through to a pair of large 3.00-inch polished stainless steel tips that finish the look with a clean, muscular appearance.
DOR / DOS Configuration
This American Thunder system is a versatile DOR/DOS (Dual Out Rear or Dual Out Side) design. You can route the tailpipes to exit either behind the rear wheels — ideal for towing — or straight out the back under the rear bumper for an aggressive, muscular stance. Because the pipes use the factory hanger locations, the configuration you choose bolts up cleanly with no fabrication required.
Key Benefits
- Deep, aggressive exterior sound with a moderate interior tone thanks to the Super 40™ Series muffler
- 16-gauge mandrel-bent aluminized steel construction for smooth, unrestricted flow
- Dual 2.50-inch aluminized steel tailpipes topped with 3.00-inch polished stainless steel tips
- Choice of dual-out-rear or dual-out-side routing to match towing or styling priorities
- Uses factory hanger locations for a straightforward, at-home installation
- CARB (California) compliant and emissions-legal (Emission Code 5)
Fitment
Designed specifically for 2004-2008 Ford F-150 and Lincoln Mark LT trucks with the 4.6L or 5.4L engine, this system fits both 2- and 4-wheel drive models. Every kit includes the muffler and all necessary parts and hardware for an easy installation you can complete in your own garage. Please note this system does not include a heat shield.
Warranty & Alternatives
The American Thunder cat-back system is covered by Flowmaster’s 3-year Limited Warranty. If you prefer all stainless steel construction backed by a Lifetime Limited Warranty, consider Flowmaster exhaust system #817417. This product carries a California Proposition 65 warning.
