Description
Overview
The Flowmaster Flow FX Cat-back Exhaust System is a complete bolt-on upgrade engineered for 2019*–2026 GM Silverado/Sierra 1500 trucks (*new body style) equipped with the 5.3L engine and factory dual exhaust. Built to deliver a deep, moderately aggressive tone alongside real performance gains, this Flow FX system replaces your restrictive factory piping with a free-flowing, straight-through design that lets your 5.3L breathe. With maximum dyno gains of 21 horsepower and 26 lb-ft of torque at the rear wheels, it’s a smart way to wake up your truck without sacrificing durability or that factory-clean look.
Key Benefits
At the heart of the system is the single inlet/dual outlet Flow FX straight-through muffler, measuring 24 inches in overall length with a center inlet and dual 2.50-inch outlets. Fed by a 3.00-inch inlet pipe, this straight-through architecture maximizes flow for that unmistakable aggressive-yet-moderate Flowmaster sound. The entire system is manufactured from durable 409 stainless steel throughout, standing up to heat, road spray, and years of hard use.
The dual 2.50-inch mandrel-bent tailpipes are custom routed to clear the factory spare tire and tow hitch with no clearance issues, then exit through the factory exhaust bezels in the bumper. That means you keep the clean, factory dual exhaust appearance while gaining serious flow and a bolder note. Best of all, this system is CARB (California) compliant, so it’s a legal upgrade in emissions-restricted states.
Highlights
- Constructed from durable 409 stainless steel for long-lasting corrosion resistance
- 3.00-inch inlet pipe feeding a straight-through Flow FX muffler for maximum flow
- Maximum dyno gains of 21 hp and 26 lb-ft at the rear wheels
- Dual 2.50-inch mandrel-bent tailpipes routed to clear the spare tire and tow hitch
- Exits through factory bumper bezels to retain the factory dual exhaust look
- CARB compliant — legal in all 50 states
Sound & Performance
The Flow FX series is tuned for drivers who want an aggressive, deep exhaust note that stays moderate enough for daily driving and towing. The straight-through muffler design frees up exhaust flow to unlock the power and torque your 5.3L has been holding back, giving you both a better sound and a stronger pull.
Fitment & Installation
This cat-back system fits both 2WD and 4WD 2019*–2026 Silverado/Sierra 1500 models (*new body style) with the 5.3L engine and factory dual exhaust. It utilizes the factory hanger locations and includes installation instructions plus all necessary hardware for a straightforward at-home installation. Please note: the muffler is supplied as part of the kit, exhaust tips are sold separately, and no heat shield is included.
Warning: This product can expose you to chemicals known to the State of California under Proposition 65.









