5″ Down Pipe Back Exhaust 2011 – 2015 GM 6.6L Duramax Full Exhaust Pipe Kit

This is a 5″ downpipe-back exhaust system designed for 2011–2015 Chevrolet Silverado & GMC Sierra 2500/3500HD trucks with the 6.6L Duramax LML engine. Here’s a detailed breakdown:

Key Features & Fitment:

• Fits: 2011–2015 Chevy Silverado & GMC Sierra 2500/3500HD (pickup models only—not Cab & Chassis).

• Engine Compatibility: LML Duramax (2011–2015).

• 5″ diameter piping for improved exhaust flow over stock.

• Removes catalytic converter & DPF (for off-road use only—not street legal in the U.S. due to EPA regulations).

• Bolt-on direct fit—uses OEM hangers and includes all necessary hardware (gaskets, clamps, etc.).

• Full exhaust kit (downpipe-back, meaning it replaces everything from the turbo outlet to the tailpipe).

Performance & Sound:

• Reduced backpressure for better turbo spool and potential power gains (best paired with a tune).

• Louder exhaust tone than stock, but the inclusion of a muffler helps control drone compared to a straight-pipe setup.

Installation Notes:

• Should be a bolt-on installation with basic tools.

• May require lifting the truck for easier access.

• Tuning required if deleting the DPF—the truck will throw emissions-related fault codes without a proper tune.

Legal & Tuning Considerations:

• Off-road/racing use only—federal law prohibits tampering with emissions systems (DPF/DEF/catalytic converter) on street-driven vehicles.

• Required supporting mods:

  • A DPF/DEF delete tune (from a reputable tuner like EFI Live, PPEI, or Duramaxtuner) to prevent check engine lights and regen issues.

  • EGR block-off plates (optional but recommended for full deletes).

Would you like recommendations for tuners or additional performance upgrades to pair with this exhaust?