The Flowmaster® Flow FX Extreme Stainless Steel Cat-Back Exhaust System is engineered for maximum performance, improved durability, and an aggressive-to-moderate exhaust tone. Designed for 2014–2019 Chevrolet and GMC Silverado/Sierra 1500 models equipped with the 4.3L or 5.3L engine, this system delivers noticeable gains in power and sound.

Featuring a high-flow Flow FX performance muffler and 3.00-inch mandrel-bent 409 stainless steel tubing, the system increases exhaust flow for enhanced horsepower and torque. Flowmaster dyno testing shows gains of up to 11 hp and 15 lb-ft at the rear wheels.

Key Features:
• Flow FX series performance muffler with aggressive-to-moderate sound level
• 3.00-inch mandrel-bent 409 stainless steel tubing for maximum flow
• Turndown dump-style exit for improved off-road clearance
• Dyno-proven gains: +11 hp and +15 lb-ft at the wheels
• 409 stainless steel construction for long-lasting durability
• Includes all hardware for an at-home installation
• Uses factory hanger locations
• Lifetime Limited Warranty

Fitment 

Fits 2014–2019 Chevrolet Silverado 1500 with 4.3L engine
Fits 2014–2019 Chevrolet Silverado 1500 with 5.3L engine
Fits 2014–2019 GMC Sierra 1500 with 4.3L engine
Fits 2014–2019 GMC Sierra 1500 with 5.3L engine

The Flow FX Extreme design uses a turndown dump-style exit directly after the muffler, eliminating the over-axle tailpipe. This improves ground clearance and departure angle, making it ideal for off-road use and lifted trucks. The system reuses factory hanger locations, includes all required hardware, and is backed by Flowmaster’s Lifetime Limited Warranty.