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 6.6L Duramax LML features a heavy, highly restrictive factory emissions mid-section and necked-down tailpipe that trap extreme thermal heat behind the turbo housing. These restrictive components trigger constant fuel-wasting active regens, raise towing EGTs, and cause DEF sensor failures that lock your work truck into Limp Mode.
- The 4" LML Turbo Downpipe-Back Race Exhaust Kit is a complete, unhindered exhaust solution. By dropping system backpressure to near zero, it sharply lowers towing EGTs, restores fast turbo spool-up, improves fuel economy by 2–3 MPG, and delivers an aggressive, deep V8 diesel tone.
Key Features
- Premium Material: Full 4-inch mandrel-bent T409 stainless steel tubing built to resist thermal expansion, road salt, and harsh winter chassis rust.
- Unleash Unmistakable V8 Turbo Sound: Removes all restrictive emissions baffles to restore a deep, throaty diesel V8 roar and crisp turbo spool whistle under acceleration.
- Sharply Drop Towing EGTs: Flushes out extreme exhaust backpressure right behind the turbo downpipe, allowing hot exhaust gases to exit rapidly to protect your LML V8 during heavy towing.
- Permanently Eliminate DEF & DPF Errors: Stops failure-prone DEF heaters, pumps, and NOx sensors that trigger automatic 55-MPH dealer Limp Mode lockouts.
FAQ
Q: What is the difference between a "Mid-Pipe Delete Pipe" and this "Downpipe-Back Kit"?
A: Mid-pipe delete pipe only replaces the center DPF/SCR emissions canisters while reusing your factory rear tailpipe. This Downpipe-Back Kit replaces the entire system from the turbo downpipe flange all the way to the rear bumper exit, providing maximum airflow, lower EGTs, and a clean, consistent 4-inch diameter throughout.
Q: Does this kit replace the front downpipe off the turbo charger?
A: No. This is a Downpipe-Back system, meaning it bolts directly to the outlet flange of your stock turbo downpipe. It replaces everything downstream from that downpipe outlet flange to the rear exit.
Q: Do I need to reinstall factory EGT sensors or DEF injectors into this pipe?
A: No. This is a smooth, bungless straight-pipe design. Once your ECM is flashed with a delete tune, these sensors are electronically deactivated—simply unplug the harnesses and zip-tie them safely to the frame.
Q: Will this 4" kit fit both Short Bed and Long Bed trucks?
A: Yes. The kit includes modular extension pipe sections designed to accommodate all cab and bed lengths. You simply trim the straight extension pipe section during installation based on your specific wheelbase.
