Flowmaster® (19-21) Silverado/Sierra 409SS American Thunder Cat-Back System (Crew/Double Cab)

  • Sale
  • Regular price $830.95

Compatible: (5.3L)

2019 - 2021 Chevy Silverado (NEW BODY STYLE)

2019 - 2021 GMC Sierra  (NEW BODY STYLE)


Does Not fit 2019 LD/classic body style or trucks with factory single exhaust system.

This part is legal for sale or use on Emissions Controlled Vehicles, Uncontrolled (Non-Emissions Controlled) Vehicles, and Racing Use Only Vehicles because it does not affect vehicle emissions and is not covered by emissions regulations.




The new Flowmaster® American Thunder® cat-back exhaust system for the 2019-2021 GM 1500 (new body style) trucks with 5.3L engine is perfect for the person looking for an aggressive sound level outside the truck, with a moderate interior tone and the performance benefits you would expect from Flowmaster. This emissions-legal bolt-on system fits all Crew Cab and Double Cab models with 5.5 and 6.5-ft long beds with factory dual exhaust option. Features include flex joint, mandrel-bent 3.00-inch stainless steel tubing flowing into a Super 40® Series muffler, dual 2.50-inch mandrel-bent stainless tailpipes that are finished off with quad 4.00-inch black ceramic coated stainless steel tips exiting out under the factory exhaust bezels. Designed for an easy fit, this system includes all necessary parts and hardware for an easy at home installation. Notes: Fits 2019-2020 Chevrolet Silverado 1500 and GMC Sierra 1500 Crew Cab and Double Cab models with 5.3L engine. Fits models with 5.5 and 6.5-ft long beds with factory dual exhaust option.


  • Large 4.00-inch Black Ceramic Coated Stainless Quad Tips
  • Moderate Interior with Aggressive Exterior Tone
  • Uses the Factory Hanger Locations
  • Large Volume Super 40 Muffler
  • Stainless Steel Construction
  • Lifetime Limited Warranty
  • Easy Installation

Brand Flowmaster
Emission Code 5
Exhaust Series American Thunder
Exit Position Dual Out Rear
Material 409 Stainless Steel
Mount Type Uses Factory Hangers
Muffler Series Super 40 Series
Product Type Exhaust System
Sound Level Aggressive / Moderate
System Type Cat-back
Tip Diameter 4
Tip Material 304 Stainless
Tip Shape Round
Tubing Diameter (in) 3/2.5
Tubing Material 409S Stainless Steel
California Proposition 65 Chemical Name Chromium (hexavalent compounds)
Nickel (Metallic)
California Proposition 65 Required Yes
Part Number 817895


Install Guide: