Upgraded 3" 304 Stainless Downpipe Exhaust for 2015.5-2016 LML 6.6L Duramax Diesel

Upgrade 3" 304 Stainless Downpipe Exhaust | 2015.5-2016 GM 6.6L Duramax (LML)

Unlock the full breathing capacity of your LML Duramax’s turbocharger. This 3-inch performance downpipe is the single most effective hardware upgrade for 2015.5–2016 Chevrolet Silverado and GMC Sierra 2500HD/3500HD trucks equipped with the 6.6L Duramax diesel engine.

Key Features

• T304 Industrial-Grade Stainless Steel: Built to withstand extreme heat cycles without cracking, warping, or corroding. Unlike cheaper 409-grade alternatives, our T304 construction ensures a lifetime of rust-free, high-performance durability.
• Massive 3-Inch High-Flow Design: Significantly larger than the restrictive factory downpipe; this eliminates the primary "cork" at the turbocharger outlet for maximum exhaust velocity.
• Drastically Lower EGTs: Getting hot exhaust gases out of the turbo housing faster is critical for the LML platform. Lower EGTs protect your turbo internals, pistons, and head gaskets during heavy towing or high-boost operation.
• Instantaneous Turbo Spool-Up: Reducing backpressure at the turbine exit minimizes turbo lag, giving you sharper, more immediate torque when you step on the pedal.
• Perfect Chassis Clearance: Custom-bent specifically for the tight engine bay clearances of the 2015.5+ GM chassis, ensuring no vibrations or contact against the firewall or drivetrain components.
• Premium Heat Retention: Engineered to provide optimal flow characteristics that help maintain exhaust energy needed for efficient VGT (Variable Geometry Turbo) operation.

What’s New? Key Upgrades Over the Previous Model

• Premium 304 Stainless Steel Construction: We've completely phased out the old 201 stainless steel and iron flanges, which were vulnerable to heat-induced rust and warping. The new system is built entirely from 304 stainless steel—offering unmatched resistance to heat, corrosion, and salt spray for a rock-solid, leak-proof seal that lasts.

• Race-Spec Black Heat Wrap: Say goodbye to the old linen-colored wrap that faded and crumbled over time. We've upgraded to a durable black fiberglass heat wrap that not only resists aging and peeling but also provides superior heat shielding. It keeps under-hood temperatures down and gives your setup a sleek, professional race-car look.

Shipping & Returns

Free & Fast Shipping Policy

Your order will be dispatched within 1-2 business days, and the package is expected to arrive by the estimated delivery date. Click for Shipping Policy.

Free & Easy Return Policy

Every order comes with a 14-day free return, which means you don't have to pay for a return slip. Click for Return Policy.

• 2015.5–2016 Chevrolet Silverado 2500HD / 3500HD (6.6L Duramax LML)
• 2015.5–2016 GMC Sierra 2500HD / 3500HD (6.6L Duramax LML)