Description
Overview
The Flowmaster American Thunder Cat-back Exhaust System transforms the exhaust note of your 2004-2008 Ford F-150 or Lincoln Mark LT equipped with the 4.6L or 5.4L engine. Engineered for the driver who wants a deep, aggressive exterior sound paired with a moderate interior tone, this bolt-on kit delivers the performance benefits and unmistakable character that the American Thunder series is known for.
Built as a complete cat-back package, the system replaces your restrictive factory piping with 16-gauge mandrel-bent stainless steel tubing that flows freely into a specially designed Super 40 Series performance muffler. The result is a truck that breathes better and sounds every bit as capable as it looks, without a drone-heavy cabin.
Key Benefits
At the heart of the system is the Super 40 Series muffler, a proven performer that produces an aggressive, muscular tone while keeping the interior sound at a moderate, livable level. Dual 2.50-inch stainless steel tailpipes carry the flow rearward and are finished with a pair of large 3.00-inch polished stainless steel tips that give the back of your truck a serious upgrade in appearance.
- 16-gauge mandrel-bent stainless steel tubing for smooth, unrestricted flow
- Super 40 Series performance muffler included for a deep, aggressive exterior sound
- Dual 2.50-inch stainless steel tailpipes with 3.00-inch polished stainless tips
- 3.00-inch inlet diameter with dual tail pipe configuration
- Uses factory hanger locations and includes all necessary parts and hardware
- CARB (California) compliant, emissions-legal DOR/DOS design
Configuration & Exit Options
This is a DOR/DOS (Dual Out Rear or Dual Out Side) system, giving you flexibility in how the tailpipes exit. Route them to exit behind the rear wheels — an ideal setup for towing — or send them straight out the back under the rear bumper for a bold, muscular look. Either way, the polished stainless tips finish the install with a premium appearance.
Fitment
Designed specifically for the 2004-2008 Ford F-150 and Lincoln Mark LT with the 4.6L or 5.4L engine, this system fits both 2-wheel drive and 4-wheel drive models. Because it uses the factory hanger locations, installation is a straightforward, bolt-on job you can complete at home with the included hardware.
Warranty & Alternatives
This stainless steel system is backed by a Lifetime Limited Warranty. If you prefer all aluminized steel construction with a 3-year Limited Warranty, the alternative exhaust system #17417 offers the same American Thunder performance in a different material. Note that this system does not include a heat shield. California Proposition 65 warning applies.









