FITMENT
- 2011-2015.5 6.6L Silverado & Sierra Duramax 2500HD/3500HD with LML Diesel engine pickup.
- This downpipe features a V-Band connection flange at the turbo outlet.
- NOT directly fit 2015.5-2016 models with the 3-bolt flange exhaust system unless the downstream system is modified.
DESCRIPTION
Product Overview
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The factory downpipe on 11-15.5 Duramax LML trucks is a major performance bottleneck. To squeeze past tight engine bay clearances, GM engineers severely crushed and flattened the stock pipe.
- This restricted "pancake" design chokes exhaust flow, traps excessive thermal energy right at the turbo charger, and spikes EGTs under heavy towing loads.
- Upgrading to smooth, 3-inch mandrel-bent downpipe maximizes exhaust flow right from the turbo outlet, rapidly dropping EGTs and allowing the turbo to spool up much faster.
Key Features
- Heavy-Duty Wrapped Protection: Crafted from high-grade 304 stainless steel and wrapped in premium heat-insulating sleeve to safeguard surrounding engine bay components.
- TIG-Welded Construction: All joints are precision TIG welded and jig-built to prevent cracking under high thermal cycling and aggressive vibration.
- Unrestricted 3" Bore: Replaces the restrictive, "crushed" factory oval pipe with a true, consistent 3“ mandrel-bent round diameter through every turn.
- Drastic EGT Reduction: Smooths out exhaust flow to quickly draw extreme heat away from the turbo, reducing under-hood temperatures and protecting engine health.
FAQ
Q: Will this fit my 2015 or 2016 model?
A: It fits 11-15.5 models that use a V-band style turbo connection. In 15.5-16, GM switched the LML to a 3-bolt flange style downpipe. Please inspect your truck's connection before buying.
Q: Does this pipe have the necessary sensor ports?
A: Yes. Unlike older generations, the LML downpipe requires sensor ports. This downpipe is precision-engineered with 3 factory-location bungs to house your stock EGT sensor, NOx sensor, and 9th injector dosing valve flawlessly.
Q: What happens to the sensor bungs if I delete my truck?
A: If you are doing an emissions delete and removing these sensors, you must buy a standard LML downpipe plug kit (or sourcing matching bolts/plugs) to cap the 3 bungs off so exhaust gas doesn't leak out.
Q: Will this 3" downpipe work with my stock exhaust or an aftermarket 4"/5" delete pipe?
A: Yes, it fits both perfectly. The OEM-matched flanges bolt directly to the stock turbo and factory exhaust. If you upgrade to a 4" or 5" delete pipe, it still fits flawlessly—all downpipe-back systems neck down to bolt directly to this factory location without adapters.
