Flowmaster 20-25 GM 2500HD 6.6L CCB Outlaw Cat-Back Exhaust System

This Flowmaster® Outlaw® Cat-back exhaust system for the 2020-2026 Chevy Silverado and GMC Sierra 2500HD/3500HD trucks with the 6.6L gas engine, is perfect if you are looking for an aggressive sound level inside and outside of the truck, with all of the performance benefits that you would expect from Flowmaster®. Maximum increases of up to 9 hp and 9 lb.ft. over the stock exhaust at the rear wheels. Designed for the Crew Cab, Standard Bed (6.5 ft.) models only, this bolt-on, emissions-legal system features a stainless steel Outlaw series muffler and large dual 3.00-inch 409 stainless steel mandrel-bent tailpipes that can be configured to exit either dual straight out the back, or dual out the sides behind the rear wheels which is best suited for towing applications. The system is finished off with polished 4.00-inch stainless steel tips and is covered by our Lifetime Limited Warranty. Designed for an easy fit, this system includes all necessary parts and hardware for installation. Fits 2020-2026 GM Silverado/Sierra 2500HD/3500HD 6.6L Gas V8, Outlaw Series, 3.50" to Dual 3.00" Cat-Back, Dual Rear Exit, Stainless Steel Exhaust System Fits Crew Cab with 6.5-foot bed length, 159-inch wheelbase only. Will not fit models with 5th wheel tow hitch installed.

• 3.50-inch and 3.00-inch mandrel bent 16-gauge 409 stainless steel tubing maximizes exhaust flow and improves durability
• Super 10 Series performance muffler delivers a deep, aggressive performance tone and improves exhaust flow
• Includes complete hardware and factory styled hangers in the stock locations for an easy installation
• Can be configured to exit straight out the rear or out the side depending on preference
• Max increases of up to 9 hp and 9 lb.ft. over the stock exhaust at the rear wheels
• Dual 4.00-inch polished stainless steel tips add a custom look
• Backed by Flowmaster’s Lifetime Limited Warranty

Upgrade your 2020-2026 Chevrolet Silverado or GMC Sierra 2500HD/3500HD with the Flowmaster Outlaw Cat-Back Exhaust System, part number 818112. Designed for 6.6L gas V8 Crew Cab trucks with the 6.5-foot standard bed and 159-inch wheelbase, this emissions-legal system delivers an aggressive exhaust note inside and outside the vehicle while improving exhaust flow. Testing shows maximum gains of up to 9 horsepower and 9 lb.-ft. of torque over the stock exhaust at the rear wheels.
Built for durability and performance, the system uses 3.50-inch and dual 3.00-inch 16-gauge 409 stainless steel mandrel-bent tubing. The included Outlaw/Super 10 Series performance muffler produces a deep, aggressive tone and supports efficient exhaust flow. Dual 4.00-inch polished stainless steel tips provide a clean, custom appearance, while the tailpipes can be configured for a straight rear exit or side exit behind the rear wheels. The side-exit configuration is especially well suited for towing applications.
The Flowmaster 818112 is engineered as a bolt-on installation using factory-style hangers in the stock locations and includes the necessary hardware for installation. It is intended only for Crew Cab, standard-bed models and will not fit trucks equipped with an installed fifth-wheel tow hitch. Flowmaster backs this exhaust system with a Lifetime Limited Warranty. Review vehicle fitment and applicable emissions requirements before installation.

Features:

• Fitment: Designed for 2020-2026 Chevrolet Silverado and GMC Sierra 2500HD/3500HD trucks with the 6.6L gas V8, Crew Cab, standard bed, and 159-inch wheelbase

• Construction: 3.50-inch inlet and dual 3.00-inch 16-gauge 409 stainless steel mandrel-bent tubing for improved flow and durability

• Muffler: Outlaw/Super 10 Series performance muffler delivers a deep, aggressive exhaust tone

• Exhaust Exit: Configurable for dual straight rear exit or dual side exit behind the rear wheels

• Performance: Provides maximum gains of up to 9 horsepower and 9 lb.-ft. of torque over the stock exhaust at the rear wheels

• Exhaust Tips: Includes dual 4.00-inch polished stainless steel tips

• Installation: Bolt-on design with factory-style hangers, complete hardware, and stock mounting locations

• Warranty: Covered by Flowmaster’s Lifetime Limited Warranty

Fitment:
Chevrolet Silverado 2500 HD Custom 2020
Chevrolet Silverado 2500 HD Custom 2021
Chevrolet Silverado 2500 HD Custom 2022
Chevrolet Silverado 2500 HD Custom 2023
Chevrolet Silverado 2500 HD Custom 2024
Chevrolet Silverado 2500 HD Custom 2025
Chevrolet Silverado 2500 HD Custom 2026
Chevrolet Silverado 2500 HD High Country 2020
Chevrolet Silverado 2500 HD High Country 2021
Chevrolet Silverado 2500 HD High Country 2022
Chevrolet Silverado 2500 HD High Country 2023
Chevrolet Silverado 2500 HD High Country 2024
Chevrolet Silverado 2500 HD High Country 2025
Chevrolet Silverado 2500 HD High Country 2026
Chevrolet Silverado 2500 HD LT 2020
Chevrolet Silverado 2500 HD LT 2021
Chevrolet Silverado 2500 HD LT 2022
Chevrolet Silverado 2500 HD LT 2023
Chevrolet Silverado 2500 HD LT 2024
Chevrolet Silverado 2500 HD LT 2025
Chevrolet Silverado 2500 HD LT 2026
Chevrolet Silverado 2500 HD LTZ 2020
Chevrolet Silverado 2500 HD LTZ 2021
Chevrolet Silverado 2500 HD LTZ 2022
Chevrolet Silverado 2500 HD LTZ 2023
Chevrolet Silverado 2500 HD LTZ 2024
Chevrolet Silverado 2500 HD LTZ 2025
Chevrolet Silverado 2500 HD LTZ 2026
Chevrolet Silverado 2500 HD WT 2020
Chevrolet Silverado 2500 HD WT 2021
Chevrolet Silverado 2500 HD WT 2022
Chevrolet Silverado 2500 HD WT 2023
Chevrolet Silverado 2500 HD WT 2024
Chevrolet Silverado 2500 HD WT 2025
Chevrolet Silverado 2500 HD WT 2026
Chevrolet Silverado 2500 HD ZR2 2024
Chevrolet Silverado 2500 HD ZR2 2025
Chevrolet Silverado 2500 HD ZR2 2026
Chevrolet Silverado 3500 HD High Country 2020
Chevrolet Silverado 3500 HD High Country 2021
Chevrolet Silverado 3500 HD High Country 2022
Chevrolet Silverado 3500 HD High Country 2023
Chevrolet Silverado 3500 HD High Country 2024
Chevrolet Silverado 3500 HD High Country 2025
Chevrolet Silverado 3500 HD High Country 2026
Chevrolet Silverado 3500 HD LT 2020
Chevrolet Silverado 3500 HD LT 2021
Chevrolet Silverado 3500 HD LT 2022
Chevrolet Silverado 3500 HD LT 2023
Chevrolet Silverado 3500 HD LT 2024
Chevrolet Silverado 3500 HD LT 2025
Chevrolet Silverado 3500 HD LT 2026
Chevrolet Silverado 3500 HD LTZ 2020
Chevrolet Silverado 3500 HD LTZ 2021
Chevrolet Silverado 3500 HD LTZ 2022
Chevrolet Silverado 3500 HD LTZ 2023
Chevrolet Silverado 3500 HD LTZ 2024
Chevrolet Silverado 3500 HD LTZ 2025
Chevrolet Silverado 3500 HD LTZ 2026
Chevrolet Silverado 3500 HD WT 2020
Chevrolet Silverado 3500 HD WT 2021
Chevrolet Silverado 3500 HD WT 2022
Chevrolet Silverado 3500 HD WT 2023
Chevrolet Silverado 3500 HD WT 2024
Chevrolet Silverado 3500 HD WT 2025
Chevrolet Silverado 3500 HD WT 2026
GMC Sierra 2500 HD AT4 2020
GMC Sierra 2500 HD AT4 2021
GMC Sierra 2500 HD AT4 2022
GMC Sierra 2500 HD AT4 2023
GMC Sierra 2500 HD AT4 2024
GMC Sierra 2500 HD AT4 2025
GMC Sierra 2500 HD AT4 2026
GMC Sierra 2500 HD AT4X 2024
GMC Sierra 2500 HD AT4X 2025
GMC Sierra 2500 HD AT4X 2026
GMC Sierra 2500 HD Base 2020
GMC Sierra 2500 HD Base 2021
GMC Sierra 2500 HD Denali 2020
GMC Sierra 2500 HD Denali 2021
GMC Sierra 2500 HD Denali 2022
GMC Sierra 2500 HD Denali 2023
GMC Sierra 2500 HD Denali 2024
GMC Sierra 2500 HD Denali 2025
GMC Sierra 2500 HD Denali 2026
GMC Sierra 2500 HD Pro 2023
GMC Sierra 2500 HD Pro 2024
GMC Sierra 2500 HD Pro 2025
GMC Sierra 2500 HD Pro 2026
GMC Sierra 2500 HD SLE 2020
GMC Sierra 2500 HD SLE 2021
GMC Sierra 2500 HD SLE 2022
GMC Sierra 2500 HD SLE 2023
GMC Sierra 2500 HD SLE 2024
GMC Sierra 2500 HD SLE 2025
GMC Sierra 2500 HD SLE 2026
GMC Sierra 2500 HD SLT 2020
GMC Sierra 2500 HD SLT 2021
GMC Sierra 2500 HD SLT 2022
GMC Sierra 2500 HD SLT 2023
GMC Sierra 2500 HD SLT 2024
GMC Sierra 2500 HD SLT 2025
GMC Sierra 2500 HD SLT 2026
GMC Sierra 3500 HD AT4 2020
GMC Sierra 3500 HD AT4 2021
GMC Sierra 3500 HD AT4 2022
GMC Sierra 3500 HD AT4 2023
GMC Sierra 3500 HD AT4 2024
GMC Sierra 3500 HD AT4 2025
GMC Sierra 3500 HD AT4 2026
GMC Sierra 3500 HD Base 2020
GMC Sierra 3500 HD Base 2021
GMC Sierra 3500 HD Denali 2020
GMC Sierra 3500 HD Denali 2021
GMC Sierra 3500 HD Denali 2022
GMC Sierra 3500 HD Denali 2023
GMC Sierra 3500 HD Denali 2024
GMC Sierra 3500 HD Denali 2025
GMC Sierra 3500 HD Denali 2026
GMC Sierra 3500 HD Pro 2023
GMC Sierra 3500 HD Pro 2024
GMC Sierra 3500 HD Pro 2025
GMC Sierra 3500 HD Pro 2026
GMC Sierra 3500 HD SLE 2020
GMC Sierra 3500 HD SLE 2021
GMC Sierra 3500 HD SLE 2022
GMC Sierra 3500 HD SLE 2023
GMC Sierra 3500 HD SLE 2024
GMC Sierra 3500 HD SLE 2025
GMC Sierra 3500 HD SLE 2026
GMC Sierra 3500 HD SLT 2020
GMC Sierra 3500 HD SLT 2021
GMC Sierra 3500 HD SLT 2022
GMC Sierra 3500 HD SLT 2023
GMC Sierra 3500 HD SLT 2024
GMC Sierra 3500 HD SLT 2025
GMC Sierra 3500 HD SLT 2026