Description
Overview
The Flowmaster Flow FX Cat-Back Exhaust System is a bolt-on upgrade engineered for 2011-2019 GM Silverado/Sierra 2500/3500 HD trucks running the 6.0-liter engine. Built to deliver stronger flow, a purposeful tone, and a clean custom look, this complete cat-back kit replaces the restrictive factory piping with a design that breathes better and sounds the part—without turning your daily driver into something you can’t live with.
Everything in this system is manufactured from durable 409 stainless steel throughout, giving you long-term corrosion resistance and rugged reliability under the truck. The 3.50-inch mandrel-bent pipes maintain a smooth, consistent diameter through every bend, promoting better exhaust gas flow from the cat-back to the tip. At the heart of the kit is the Flow FX “straight-through” muffler, tuned for a moderate sound level that adds character while keeping the cabin comfortable.
Performance
Flowmaster’s dyno testing revealed maximum increases of +21 horsepower and +23 lb-ft of torque at the rear wheels—real, measurable gains that come from freeing up the factory exhaust restriction. Paired with the straight-through muffler design, the Flow FX system is built to deliver maximum performance alongside its aggressive-yet-manageable sound.
Style & Exit
This system exits out the side, behind the rear wheel, and finishes with a 5.00-inch black ceramic tip for added style and a genuine custom look. The tip carries an embossed logo, and the silver-finished piping and muffler give the whole system a factory-tough appearance from the axle back.
Fitment & Installation
The Flow FX cat-back was specifically designed for Crew Cab Short Bed trucks with the 6.5-foot bed. It utilizes all the existing factory hanger locations for a proper, no-guesswork fit, and it ships with installation instructions plus all necessary hardware, making it a straightforward install you can tackle at home. This is a CARB (California) compliant system with Emission Code 5.
Highlights
- 409 stainless steel construction throughout for lasting durability
- 3.50-inch mandrel-bent pipes for improved exhaust gas flow
- Flow FX straight-through muffler (24.00-inch overall length, center inlet and center outlet, 3.50-inch outlet) tuned for a moderate sound level
- Dyno-verified gains of +21 hp and +23 lb-ft at the rear wheels
- Side exit behind the rear wheel with a 5.00-inch black ceramic tip and embossed logo
- Mounts using factory hangers with all hardware and instructions included
Designed to fit the 6.0-liter Silverado/Sierra 2500/3500 HD Crew Cab Short Bed, the Flowmaster Flow FX cat-back is backed by Flowmaster’s Lifetime Limited Warranty—an easy, high-value way to add power, presence, and a better sound to your heavy-duty truck.
