FITMENT

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

DESCRIPTION

Product Overview

• The early-generation 2011-2015 Duramax LML features a highly complex triple-emissions system (DPF + DOC + SCR/DEF) that chokes your engine.
• With 11 to 15.5 years on the road, these trucks have hit the peak failure window. Failed DEF heaters, drifting NOx sensors, and ash-plugged filters continuously throw fault codes, tank fuel mileage to a miserable 13-14 MPG, and trigger Limp Mode.
• Furthermore, pushing heavy loads through steep highway grades with these restrictions traps intense backpressure, spiking towing EGTs past 1,300°F.At this vehicle age, simply patching the mid-section isn't always enough—the original factory rear tailpipe and hangers are often heavily rusted, scaled, and ready to snap.

Key Features

• Rugged T-409 Stainless Steel Build: Manufactured from industrial-grade T-409 SS, perfectly optimized to expand and contract under intense thermal cycling without cracking or warping.
• Substantial EGT & Heat Reduction: Instantly drops exhaust backpressure, allowing scorching gases to exit the motor rapidly, dropping EGTs significantly under heavy sustained towing loads.
• The Deepest Acoustic V8 Growl: The huge 5" cross-sectional area acts like an acoustic megaphone, producing an exceptionally deep, deep-tone rumble that sets your truck apart from standard 4" pipes.
• Factory V-Band Connection Setup: Designed to seat perfectly against your early-model (2011-2015) downpipe exit utilizing your original factory V-band clamp for a 100% leak-free seal.

FAQ

Q: Will a 5" pipe cause me to lose low-end towing torque?

A: Yes, slightly if your truck is stock. The massive 5" diameter slows exhaust velocity at low RPMs, softening off-the-line throttle response compared to a 4" pipe. However, under aggressive tuning or heavy high-RPM towing, the massive top-end relief prevents airflow choking to unlock peak power.

Q: Does this kit also delete the SCR? Do I still need to refill DEF?

A: Yes, it deletes the SCR, meaning you no longer need DEF. This system completely eliminates the factory DOC, SCR, and DPF assemblies. Once installed with your delete software, the entire DEF injection system, tank heaters, and NOx sensors are fully deactivated.

Q: Should I buy the 4" DP-Back pipe or the 5" DP-Back pipe ?

A: Go with the 5" pipe if your LML has a built transmission and aftermarket turbo for maximum high-RPM airflow; otherwise, the 4" version delivers the exact same horsepower on a stock turbo while preserving sharper low-end throttle response.

Q: Will this system lower my EGTs when towing?

A: Yes, significantly more than any mid-section patch pipe. This system eliminates the narrow factory restrictions and uses a continuous 5" bore from the downpipe back to maximize airflow. This allows scorching exhaust gases to escape instantly, resulting in substantially lower operating EGTs under load.