Click to zoom in
-
Guaranteed Fitment
Always the correct part
-
In-House Experts
We know our products
-
Technical Support
We help with any installation questions
-
Wordwide Delivery
Fast shipping times
Flowmaster's® FlowFX Cat-Back exhaust system for the 2020-2025 GM 2500HD and 3500HD trucks with the 6.6L gas engines gives you a great way to help you customize your GM truck to your personality. This performance exhaust system fits both 2/4 Wheel drive models and is manufactured from 409 stainless steel for years of trouble-free service and performance. Features include a 3.50-inch inlet pipe leading into a 409 stainless steel Flow FX series "straight-through" muffler for great sound and maximum performance and no drone. The muffler then connects to the factory tailpipe for a simple and effective performance upgrade. Max dyno gains of 11 hp and 10 lb-ft at the rear wheels. This results in better acceleration and towing performance. The system uses all the factory hanger locations and connections for an easy installation that you can do at home. Kits include installation instructions and all necessary hardware. Backed by Flowmaster's Lifetime Limited Warranty.
This Part Fits:
| Year | Make | Model | Submodel | Notes |
|---|---|---|---|---|
| 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 | |
| 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 | |
| 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 | |
| 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 | |
| 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 | |
| 2020 | Chevrolet | Silverado 3500 HD | Base | |
| 2021 | Chevrolet | Silverado 3500 HD | Base | |
| 2022 | Chevrolet | Silverado 3500 HD | Base | |
| 2023 | Chevrolet | Silverado 3500 HD | Base | |
| 2024 | Chevrolet | Silverado 3500 HD | Base | |
| 2025 | Chevrolet | Silverado 3500 HD | Base | |
| 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 | |
| 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 | |
| 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 | |
| 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 | |
| 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 | |
| 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 | |
| 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 | |
| 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 | |
| 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 | |
| 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 | |
| 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 | |
| 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 |
Specifications:
| 2WD/4WD | 2WD |
| 2WD/4WD | 4WD |
| Automotive Item Grade | High Performance |
| Brand | Flowmaster |
| California Proposition 65 | Yes |
| California Proposition 65 Chemical Name | Chromium (hexavalent compounds) |
| California Proposition 65 Chemical Name | Nickel (Metallic) |
| California Proposition 65 Required | Yes |
| Catalytic Converter Included | No |
| 2874 | 0 |
| Category | Exhaust |
| Choose Your Part | Exhaust System |
| 3728 | Flat Band |
| 1882 | Yes |
| Color | Natural |
| Emission Code | 5 |
| Exhaust Series | FlowFX |
| Exhaust System Kit Type | Cat-Back |
| 11205 | Black |
| 9874 | Clamp-On |
| 9876 | Angled |
| Exhaust Tip Diameter | 5.00 |
| 9877 | Rolled Edge Angle Cut |
| 1163 | Black Ceramic Coating |
| 9881 | No |
| Exhaust Tip Length | 12.00 |
| 1164 | 409 Stainless Steel |
| 1161 | 1 |
| 9878 | No |
| 10980 | Round |
| 9875 | Single Wall |
| Exit Position | Single Out Side |
| Exit Position | Single Side Exit |
| 9870 | Single Out Side |
| 200 | Natural |
| 353 | No |
| 3390 | Performance |
| 4364 | Yes |
| Heat Shield | No |
| Heat Shield Included | No |
| Inlet Diameter | 3.50 |
| Inlet Position | Center |
| Inlet Tubing Diameter | 3.50 |
| 596 | Flanged |
| Main Piping Diameter | 3.50 |
| Material | 409 Stainless Steel |
| Mount Type | Uses Factory Hanger |
| 92 | No |
| Muffler Body Height | 5.00 |
| Muffler Body Length | 18.00 |
| 4372 | 409 Stainless Steel |
| 4373 | Oval |
| Muffler Body Width | 8.00 |
| Muffler Color | Natural |
| 9882 | Natural |
| 4367 | No |
| 4368 | No |
| Muffler Included | Yes |
| Muffler Inlet | Centered |
| 9962 | Slip-Fit |
| Muffler Inlet Diameter | 3.50 |
| Muffler Inlet Inside Diameter | 3.50 |
| Muffler Inlet Location | Center |
| Muffler Inlet Outside Diameter | 3.63 |
| Muffler Material | 409 Stainless Steel |
| Muffler Outlet | Centered |
| 9963 | Slip-Fit |
| Muffler Outlet Diameter | 3.50 |
| Muffler Outlet Location | Center |
| 4375 | 1 |
| 4374 | 1 |
| Muffler Series | FlowFX |
| Muffler Shape | Oval |
| 1174 | Absorption |
| Outlet Diameter | 3.50 |
| part type | Exhaust System |
| 3530 | 409 Stainless Steel |
| Product Type | Exhaust System |
| Sound Level | Aggressive / Moderate |
| 4377 | No |
| Sub Category | Exhaust and Tail Pipes |
| System Type | Cat-back |
| Tail Pipe Outlet Outside Diameter | 3.50 |
| 4376 | 1 |
| 4370 | No |
| Tip Diameter | 3.50 |
| Tip Finish | Black Ceramic Coating |
| Tip Material | 304 Stainless Steel |
| Tip Quantity | 1 |
| 1378 | Round |
| Tubing Diameter | 3.50 |
| Tubing Diameter (in) | 3.50 |
| Tubing Material | 409 Stainless Steel |
| 26 | Cat-Back |
| 6014 | No |
| 2126 | Not Applicable |
| Warning | California Proposition 65 |
| Description_INV | 20-25 GM 2500/3500HD, 6.6L, CB, FFX, SOS |
| Description_DES | Flowmaster Flow FX Cat-Back Exhaust System |
| Description_EXT | Fits 20-25 GM 2500HD/3500HD 6.6L Gas Engine FFX Cat-Back Single Exit Exhaust System, 409 stainless steel |
| Description_MKT | Flowmaster's® FlowFX Cat-Back exhaust system for the 2020-2025 GM 2500HD and 3500HD trucks with the 6.6L gas engines gives you a great way to help you customize your GM truck to your personality. This performance exhaust system fits both 2/4 Wheel drive models and is manufactured from 409 stainless steel for years of trouble-free service and performance. Features include a 3.50-inch inlet pipe leading into a 409 stainless steel Flow FX series "straight-through" muffler for great sound and maximum performance and no drone. The muffler then connects to the factory tailpipe for a simple and effective performance upgrade. Max dyno gains of 11 hp and 10 lb-ft at the rear wheels. This results in better acceleration and towing performance. The system uses all the factory hanger locations and connections for an easy installation that you can do at home. Kits include installation instructions and all necessary hardware. Backed by Flowmaster's Lifetime Limited Warranty. |
| Description_FAB | 3.5-inch mandrel bent 16-gauge 409 stainless steel tubing maximizes exhaust flow and improves durability |
| Description_FAB | Kit includes complete hardware and factory styled hangers in the stock locations for an easy installation |
| Description_FAB | A tuned Flow FX style muffler delivers a deep, aggressive to moderate performance tone and improves exhaust flow with no drone |
| Description_FAB | Max increases of up to 11 hp and 10 lb-ft over the stock exhaust at the wheels |
| Description_FAB | Tuned performance muffler eliminates interior drone |
| Description_FAB | Maintains factory warranty |
| Description_FAB | Lifetime Limited Warranty |