DPF/DEF/EGR Delete 2004-2005 LLY 6.6L Duramax All-in-One Kit

We've packaged all the necessary parts needed for you to do DPF/DEF/EGR delete on your off-road GM/Chevy with 2004-2005 LLY 6.6L Duramax engine.

In this delete kit you will receive the following items:

DPF Delete Race Pipe (4 inch or 5 inch)

EGR Delete Kit (with or without intake)

EFILive V3 Tuner (with or without SOTF)

Attention: EFI Live tuner is a custom product and cannot be returned or exchanged. Please double-check before purchasing.

Fitment

2004-2005 GMC Sierra 2500 HD / 3500 HD, LLY 6.6L Duramax Diesel Engine

2004-2005 Chevrolet Silverado 2500 HD / 3500 HD, LLY 6.6L Duramax Diesel Engine

Benefits of Delete Kit

Free-flowing exhaust system for more power and better fuel economy

Improved combustion chamber temperatures

Better longevity of your engine's cooling and exhaust system

Increased power from more powerful tune flashes

No further soot clogging or limp mode causing by emission system

How to Choose a DPF Delete?

4” vs 5” Exhaust Comparison

• 4-inch: Produces a tighter, raspier exhaust note—especially noticeable at lower RPMs. Ideal for daily driving or mildly tuned trucks where excessive drone is undesirable.
• 5-inch: Delivers a deeper, more refined tone with less high-pitch resonance. Better suited for high-output builds and towing applications, where improved exhaust flow is beneficial.

Driver Feedback Summary

• The 4" pipe works well for stock or lightly modified trucks and a quieter cabin.
• The 5" pipe is perfect for aggressive builds, deep-tone enthusiasts, and those maximizing exhaust performance.

Types of DPF Delete Exhaust

DPF Race Delete

• Removes only the DPF (retains stock downpipe)
• Offers minimal performance gains but is the most budget-friendly
• Best for cost-conscious users or avoiding emissions testing

Downpipe-Back Delete

• Replaces the exhaust from the turbo downpipe back
• Improves mid-range power and throttle response
• Ideal for street builds using the stock turbo

Turbo-Back Delete

• Full system replacement starting from the turbo outlet
• Includes a high-flow downpipe for maximum efficiency
• Reduces turbo lag and boosts top-end power
• Top choice for tuned or high-performance engines

Muffler vs. No Muffler

With Muffler

• Reduces exhaust noise for daily driving
• Slight power restriction (~5–10 HP)
• More likely to comply with local noise regulations

Straight Pipe (No Muffler)

• Loud, aggressive exhaust tone
• Unrestricted flow for maximum horsepower
• Often not street-legal due to noise and emissions rules
• Intended for off-road or race use only

Installation instructions

EFILive AutoCal Vehicle Installation

LLY EGR Delete Kit

Fast Shipping Policy

Your order will be dispatched within 1-2 business days, and the package will arrive within your order's estimated date. Click for Shipping Policy.

Easy Return Policy

Every order comes with a 14-day free return, which means you don't have to pay for a return slip. Click for Return Policy.