FITMENT

• 2015.5-2016 6.6L Silverado & Sierra Duramax 2500HD/3500HD LML engine models with the 3-bolt flange.
  
• Does NOT Fit 2011-2015.5 model with the V-Band Clamp style. 
• Please physically inspect underneath truck to verify your turbo discharge style before purchasing!

DESCRIPTION

Product Overview

• Late-model 15.5-16 Duramax LML trucks pack incredible factory performance, but the heavy, triple-layer emissions network (DPF + DOC + SCR/DEF) wrapped under the chassis acts like a breathing stranglehold.
• Over time, permanent ash accumulation completely chokes the filter ceramic bricks, triggering relentless and fuel-heavy Active Regeneration cycles.
• This chokes your fuel economy to a painful 13-14 MPG, spikes your towing EGTs past 1,300°F, and puts high structural stress on your turbo charger, frequently causing Limp Mode.

Key Features

• Mandrel-Bent Flow: CNC mandrel-bent 4" T-409 SS tubing ensures smooth, high-velocity exhaust flow. Completely unrestricted with No Bungs to interrupt the air path.
• Massive Mileage Recovery: Stops fuel-heavy active regeneration cycles permanently. No more wasting expensive diesel fuel just to forcefully bake an empty factory ceramic filter.
• Integrated High-Flow Performance Muffler: Specifically tuned to filter out harsh high-frequency exhaust notes and eliminate painful cab drone during long highway towing hauls, without restricting air volume.
• Precision-Engineered 3-Bolt Flange: Crafted with a heavy-duty, CNC machine-cut 3-bolt flange that guarantees a seamless, direct leak-free connection to 15.5-16 turbo downpipe outlet.

FAQ

Q: Exactly which portion of my truck's exhaust does this pipe replace?

A: This section pipe drops directly into your factory exhaust line under the cab, completely replacing the restrictive CAT, SCR, and DPF filters. It bolts to factory downpipe via a 3-bolt flange and joins smoothly with stock rear tailpipe.

Q: How do they compare in sound volume and cabin drone?

A: The 4" DPF Delete pipe w/Muffler filters out harsh high-frequency raspy notes and eliminates annoying highway cab drone. It is perfect for daily drivers and long-distance family towing trips where a civilized, quiet cabin is mandatory.

Q: What is the exact difference between buying this pipe "With Muffler" vs "No Muffler"?

A: Both options deliver identical performance, lower EGTs, and recovered mileage. The straight-pipe version unlocks a raw roar and sharp turbo hiss but causes highway cabin drone. This features a high-flow 4" race pipe w/muffler that eliminates harsh frequencies, keeping your cab comfortable for long towing trips.

Q: Which system is better for a stock or mildly tuned truck?

A: The 4" Race Pipe is the better choice. If your 15.5–16 LML runs a stock turbo, stock injectors, or a mild street tune, a 4" pipe provides the perfect balance. A massive 5" DP-Back pipe can slow down exhaust gas velocity at lower RPMs on a stock motor, which causes a slight loss in low-end towing torque off the line.