The Flowmaster Outlaw Cat-Back Exhaust System delivers maximum aggression, performance, and durability for your 2020–2026 GM Silverado and Sierra HD trucks equipped with the 6.6L gas V8. Engineered from high-quality 409 stainless steel with 3.50-inch to dual 3.00-inch mandrel-bent tubing, this system improves exhaust flow and unleashes gains of up to +9 horsepower and +9 lb-ft of torque at the rear wheels.

The Outlaw Series muffler provides one of Flowmaster’s most aggressive tones—loud outside with a deep, powerful presence inside the cabin. Tailpipes can be configured for dual straight-out-the-rear or dual out-the-sides, making it suitable for towing applications. The kit is finished with polished 4.00-inch double-wall stainless steel tips and installs using factory hangers for a clean, bolt-on upgrade. All required parts and hardware are included.

Key Features

• Up to +9 hp and +9 lb-ft over stock

• 3.50" to dual 3.00" mandrel-bent 409 stainless steel tubing

• Polished 4.00" stainless steel dual tips

• Outlaw (Super 10 Series) muffler for an extremely aggressive tone

• Dual rear or dual side exit configuration

• Uses factory-style hangers; includes all hardware

• Durable stainless steel construction throughout

Fitment 

• 2020–2026 Chevrolet Silverado 2500HD with 6.6L Gas V8

• 2020–2026 Chevrolet Silverado 3500HD with 6.6L Gas V8

• 2020–2026 GMC Sierra 2500HD with 6.6L Gas V8

• 2020–2026 GMC Sierra 3500HD with 6.6L Gas V8

• Designed for Crew Cab, Standard Bed (6.5 ft.) models only

Full Product Data

Brand: Flowmaster
Catalytic Converter Included: No
Catalytic Converter Quantity: 0
Category: Exhaust
Clamping Type: Flat Band
Clamps Included: Yes
Exhaust Series: Outlaw
Exhaust Tip Color: Silver
Exhaust Tip Connection: Clamp-On
Exhaust Tip Cut: Angled
Exhaust Tip Diameter: 4.00 IN
Exhaust Tip Edge: Angle Cut
Exhaust Tip Finish: Polished
Exhaust Tip Intercooled: No
Exhaust Tip Length: 13.00 IN
Exhaust Tip Material: 304 Stainless Steel
Exhaust Tip Quantity: 2
Exhaust Tip Resonated: No
Exhaust Tip Shape: Round
Exhaust Tip Wall: Double Wall
Exit Style: Dual Out Rear, Dual Out Side
Finish: Natural
Gasket or Seal Included: No
Grade Type: Performance
Hangers Included: Yes
Inlet Diameter: 3.50 IN
Inlet Type: Flanged
Main Piping Diameter: 3.00 IN
Mount Type: Uses factory hangers
Mounting Bracket Included: Yes
Muffler Body Height: 4.00 IN
Muffler Body Length: 6.50 IN
Muffler Body Material: 409 Stainless Steel
Muffler Body Shape: Oval
Muffler Body Width: 9.50 IN
Muffler Color: Black
Muffler Finish: Black High-Temperature Paint
Muffler Flanged Inlet: No
Muffler Flanged Outlet: No
Muffler Included: Yes
Muffler Inlet Connection: Slip-Fit
Muffler Inlet Inside Diameter: 3.50 IN
Muffler Inlet Location: Center
Muffler Inlet Outside Diameter: 3.63 IN
Muffler Outlet Connection: Slip-Fit
Muffler Outlet Diameter: 3.00 IN
Muffler Outlet Location: Dual
Muffler Outlet Quantity: 2
Muffler Overall Length: 12.375 IN
Muffler Part Number: Kit Only
Muffler Quantity: 1
Muffler Series: 10 Series
Muffler Type: Chambered
Part Type: Exhaust System
Pipe Color: Silver
Pipe Material: 409 Stainless Steel
Product Type: Exhaust System
Sound Level: Aggressive
Spring Bolt Kit Included: No
Sub Category: Exhaust and Tail Pipes
Tail Pipe Outlet Outside Diameter: 3.00 IN
Tail Pipe Quantity: 2
Tail Pipe Tapered Outlet: No
Tip Logo: Embossed
Type: Cat-Back
Valve Included: No
Valve Type: Not Applicable
UPC: 090127130162
Part Number: 818112