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
- In mid-2015.5, GM updated the 6.6L Duramax LML downpipe connection to a 3-hole triangular flange. Installing an earlier LML pipe on a 2015.5–2016 model results in severe fitment issues and exhaust leaks. Additionally, running a completely open straight pipe on these late LML trucks can cause intense cabin drone during highway towing.
- The 4" LML DPF Delete Pipe is engineered specifically for late-model LML trucks. The integrated high-flow straight-through performance muffler flushes out intense backpressure and lowers towing EGTs while keeping the exhaust tone deep, refined, and completely drone-free inside the cab.
Key Features
- Premium Material: Full 4-inch mandrel-bent T409 stainless steel tubing built to resist extreme thermal stress, road salt, and harsh winter corrosion.
- Sharply Lower Towing EGTs: Relieves severe turbine backpressure right behind the downpipe, allowing exhaust temperatures to drop rapidly under heavy payloads and long hill climbs.
- Permanently Stop DEF Errors: Eliminates failure-prone DEF heaters, pumps, and NOx sensors that trigger automatic 55-MPH dealer Limp Mode lockouts.
- Quiet High-Flow Performance: Deletes the choked factory DPF, CAT, and SCR while incorporating a straight-through performance muffler to eliminate harsh highway cabin drone.
FAQ
Q: How do I know if my 2015 truck is an early 2015.0 or a late 2015.5 model?
A: Check the downpipe connection where the mid-pipe attaches behind the front axle. Early 2011–2015.0 trucks feature a V-clamp. Late 2015.5–2016 trucks feature a distinct 3-bolt flange. This kit is made specifically for the 3-hole layout.
Q: Do I need to reinstall factory DEF or EGT sensors into this pipe?
A: No. This is a smooth, bungless straight pipe. 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: Do I need a custom delete tuner to run this pipe on a 2015.5–2016 LML Duramax?
A: Yes. Factory LML DEF heaters and NOx sensors frequently fail, triggering a countdown that locks your truck into a 55-MPH (or 4-MPH) Limp Mode. Removing the SCR assembly with a custom ECM tune completely bypasses these sensors, permanently eliminating limp-mode lockouts.
Q: Is custom welding required during installation?
A: No welding is required. The kit includes a pre-welded 3-hole flange, heavy-duty lap-joint band clamps, and pre-welded hanger rods that slip directly into your truck's factory rubber mounts.
