GM Duramax L5P 3.5" Down-pipe (2017-2026)

GM 6.6L Duramax L5P Down-pipe

The GM Duramax L5P 3.5" Down-pipe (2017–2026) is made for Chevrolet Silverado and GMC Sierra 2500HD and 3500HD trucks with the 6.6L Duramax L5P engine.

This down-pipe replaces the factory unit with a 3.5-inch pipe to improve exhaust flow and reduce backpressure. It completely removes the factory L5P DOC (diesel oxidation catalyst), allowing exhaust to exit the turbo more freely and reducing restriction in the exhaust system.

Built to follow OEM routing, it installs as a direct bolt-on with proper clearance and alignment. Intended for diesel truck owners and mechanics looking for a correctly sized down-pipe designed specifically for the L5P platform.

Vehicle Compatibility

• Years: 2017-2026
• Makes: Chevrolet Silverado, GMC Sierra
• Models: 2500, 3500HD
• Engine: 6.6L Duramax L5P (diesel)
• Body: Pickup

Key Features

• Premium 3.5" T409 Stainless Steel Construction
• Enhanced Flow Efficiency (20% better than stock)
• Included Heat Wrap for Optimal Temperature Control
• Improved Heat Retention for Longevity
• removes emissions equipment
• Ideal for High-Performance Applications
• Secure 4-Bolt Flange Design with Two Installed Studs
• Complete DOC Elimination for Maximum Results
• May Require Minor Adjustments for 2020+ Models