GM Duramax LLY 6.6L (2001-2021)

Maximize exhaust flow, lower EGTs, and unlock real performance from your early Duramax. This 4" or 5" Downpipe-Back Race Exhaust System is built for 2001–2007 Chevrolet Silverado and GMC Sierra 2500HD/3500HD trucks equipped with the 6.6L Duramax e...

Remove restrictive EGR components and simplify your LLY setup. This EGR Delete Kit is designed for 2004.5–2005 GM 2500HD/3500HD trucks equipped with the 6.6L LLY Duramax engine. Built for off-road and competition applications, this kit removes the...

Unlock your truck’s full capability with the EFILive AutoCal V3 DPF Delete Tuner, complete with Black Bandit custom tuning. Built for GM Duramax 6.6L engines, this tuner delivers horsepower gains, improved fuel economy, and real-time control, ens...

Upgrade Your Intake System for Maximum Durability & Flow The Duramax LLY Y-Bridge Kit is built to replace the factory intake bridge, which is prone to blowing apart under boost and causing drivability issues. This heavy-duty, high-flow system ...

Bring back the boost your Duramax was built to make. If your turbo is showing signs of wear—slow spool, inconsistent power, or oil-related issues—this direct-fit replacement restores strong, predictable performance. Built for work-truck duty and d...

Hold the boost. Protect the power. Upgrade your 2004.5–2005 LLY Duramax with a reinforced silicone intercooler hose kit built to handle heat, boost pressure, and long-term engine demands. Whether your truck is stock, tuned, towing heavy loads, or ...

Serious clamping strength for serious Duramax builds. This Gator Heavy-Duty Head Stud Kit is designed to reinforce the cylinder head sealing system on 6.6L Duramax engines from 2001–2016. Whether your truck tows heavy, runs aggressive tuning, or s...

Boost performance and reliability with this passenger side up-pipe for 2001–2016 Duramax 6.6L engines. Featuring a larger 2" diameter and durable stainless steel construction, this up-pipe replaces the OEM pipe that often develops leaks at the bel...

Unlock On-The-Fly Power for Your Duramax Boost performance and drivability with our premium DSP5 SOTF Switches, designed for seamless integration with EFI Live DSP5 tuning. These switches allow you to change tunes instantly while driving—no reflas...

Expand your EFI Live AutoCal with this Tune Package, engineered for GM Duramax trucks. Perfect for adding another vehicle to your existing AutoCal, this package provides custom tune files and optional SOTF (Shift-On-The-Fly) switch for real-time c...