Description
Overview
The Flowmaster Flow FX Cat-Back Exhaust System is engineered to transform the sound and appearance of your 1999-2007* (*Classic body) GM Silverado/Sierra 1500 equipped with a 4.3L, 4.8L or 5.3L engine. Built as a complete cat-back kit, it replaces the restrictive factory piping from the catalytic converter back, delivering a deeper, more assertive exhaust note while helping your truck breathe more freely for maximum performance.
At the heart of the system is a single-inlet, dual-outlet Flow FX “straight-through” muffler measuring 24 inches overall, with a center 2.50-inch outlet configuration tuned for a moderate sound level that’s aggressive without being overbearing. A 3.00-inch inlet pipe feeds the muffler, while dual 2.50-inch mandrel-bent tailpipes route exhaust cleanly for smooth, unrestricted flow.
Key Benefits
Constructed from durable 409 stainless steel throughout, this Flow FX cat-back is designed to stand up to the road for the long haul. The dual tailpipes exit out the side at an angle behind the rear wheels, directing exhaust away from your boat or travel trailer when towing — a smart, practical detail for anyone who works or plays with a trailer in tow.
The system is finished with a pair of large 4.50-inch diameter black ceramic coated 304S stainless steel tips featuring an embossed logo, giving your truck a custom look that pairs perfectly with that deep, performance Flow FX sound. The silver-finished pipes and muffler complete a clean, purposeful under-truck appearance.
- Durable 409 stainless steel construction throughout
- 3.00-inch inlet pipe into a straight-through Flow FX muffler (24-inch overall length)
- Dual 2.50-inch mandrel-bent tailpipes with angled side exit behind the rear wheels
- Large 4.50-inch black ceramic coated 304S stainless steel tips with embossed logo
- Moderate sound level for a deep performance tone
- CARB (California) compliant
Easy, Bolt-On Installation
This kit is designed for a straightforward install you can tackle at home. It uses all of the existing factory hanger locations and includes an additional hanger to mount the new left side tailpipe. Installation instructions and all necessary hardware are included, so you have what you need to get the job done. Please note the muffler is supplied as part of the kit only.
Fitment
Fits 1999-2007* (*Classic body) GM Silverado/Sierra 1500 with a 4.3L, 4.8L or 5.3L engine, in both 2 and 4 wheel drive configurations with a 143.5-inch wheelbase. California Proposition 65 warning applies.













