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 introduced General Motors' complex DEF system alongside the traditional DPF and CAT assemblies. This massive mid-body emissions unit creates extreme thermal heat behind the turbo, triggers frequent fuel-wasting active regens, and causes costly DEF fluid/heater sensor failures that put your work truck into speed-restricted Limp Mode.
- The 4" LML DPF, CAT & SCR Delete Race Pipe is the ultimate performance mid-pipe solution for 2011–2015 Duramax LML trucks. this straight race pipe replaces all restrictive mid-body emissions components. By restoring unhindered exhaust flow, it sharply lowers towing EGTs, improves throttle response, unlocks 2–3 MPG gains, and restores that deep, iconic Duramax V8 turbo whistle and rumble.
Key Features
- Premium Material: Full 4" mandrel-bent T409 stainless steel tubing built to resist severe thermal stress, road salt, and harsh off-road rust.
- Sharply Drop Towing EGTs: Removes intense turbine backpressure right behind the downpipe, allowing hot exhaust gases to flush out rapidly to lower EGTs under heavy loads.
- Permanently Stop DEF System Errors: Eliminates failure-prone DEF pumps, heaters, and fluid sensors that trigger automatic 55-MPH dealer Limp Mode lockouts.
- Eliminate LML Emissions Restrictions: Completely replaces the heavy, choked factory DPF, CAT, and SCR (DEF system) mid-section with a high-flow 4-inch straight race pipe.
FAQ
Q: How does deleting the SCR/DEF system on a 2011–2015 LML Duramax prevent 55-MPH Limp Mode?
A: Factory LML DEF heaters and NOx sensors frequently fail, triggering a countdown that locks your truck into a 55-MPH Limp Mode. Removing the SCR assembly with a custom ECM tune completely bypasses these sensors, permanently eliminating limp-mode lockouts.
Q: Will this 4" race pipe clear trucks equipped with aftermarket high-capacity fuel tanks?
A: Yes. The 4" mandrel-bent tubing is contoured to follow GM's exact OEM mid-chassis pathway, maintaining factory clearances around oversized mid-ship replacement fuel tanks and transfer pumps.
Q: Does this kit include the necessary gaskets and hardware for the front flange?
A: The kit comes complete with heavy-duty stainless steel lap-joint band clamps. It does not include a replacement front flange, as it is designed to reuse your factory downpipe flange for a precise, leak-free OEM fitment.
Q: Can I convert this straight race pipe to a muffled setup later if it feels too loud while towing?
A: Yes. Because the pipe utilizes modular slip-fit connections, you can easily unclamp one of the straight 4" sections and slip in any standard 4" ID/OD high-flow performance diesel muffler at a later time.
