• Cold Air Intake for GMC Sierra Chevy Silverado 2500HD 3500 (2004-2005) 6.6L V8 Diesel Engine

Cold Air Intake for GMC Sierra Chevy Silverado 2500HD 3500 (2004-2005) 6.6L V8 Diesel Engine

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$139.99
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High-Performance Cold Air Intake System for 2004-2005 GM 6.6L V8 Duramax

Unleash the full potential of your heavy-duty workhorse.

The 2004–2005 GM Duramax (LLY) is legendary for its raw torque and towing capability, but it has always suffered from one major factory flaw: it can't breathe. The restrictive stock airbox chokes your turbo, leading to higher exhaust gas temperatures (EGTs) and sluggish throttle response when you need power the most.

Imagine merging onto the highway with a heavy trailer and feeling instant, responsive power instead of lag. This High-Performance Cold Air Induction System is engineered specifically for the 6.6L V8 diesel engine to replace those restrictive factory bottlenecks with high-velocity aluminum piping.

By drawing cooler, denser air from the fender well and shielding it from engine bay heat, this system ensures your engine runs more efficiently. Whether you are climbing steep grades, towing heavy loads, or tearing up off-road trails, give your truck the oxygen it needs to dominate the road.

Why Upgrade Your Duramax Intake?

  • Maximize Horsepower & Torque: By streamlining the airflow path, this system creates a more efficient combustion cycle, unlocking the guaranteed power gains your engine was built to deliver.
  • Lower EGTs & Better Efficiency: Cooler air means a denser oxygen charge. This helps keep Exhaust Gas Temperatures down during heavy towing and improves fuel combustion, potentially boosting your MPG on long hauls.
  • Aggressive Turbo Sound: Ditch the silence. This open-element intake amplifies the sound of your turbocharger, giving you that distinct, authoritative "turbo whistle" that diesel enthusiasts love.
  • Eliminate Heat Soak: The included heavy-duty thermal heat shield isolates the filter from the hot engine bay, ensuring the intake only draws fresh, cool air from the fender well.
  • Built for Durability: Constructed with scratch-resistant aluminum piping and reinforced couplers, this system is designed to withstand the high-vibration environment of a diesel engine bay.

Vehicle Fitment

This system is a direct bolt-on upgrade for the following GM 6.6L V8 Duramax trucks:

  • 2004–2005 Chevrolet Silverado 2500 HD
  • 2004–2005 Chevrolet Silverado 3500
  • 2004–2005 GMC Sierra 2500 HD
  • 2004–2005 GMC Sierra 3500

What's Included in the Box?

We provide everything you need for a hassle-free installation:

  • Polished, scratch-resistant aluminum induction piping
  • Premium high-flow, washable/reusable performance air filter
  • Heavy-duty thermal heat shield
  • Industrial-grade silicone couplers and vacuum hoses
  • All necessary mounting brackets and clamps

Technical Specifications

  • System Type: Fender-well cold air draw with heat shield
  • Filter Type: High-flow, reusable (washable)
  • Installation: Direct bolt-on (requires reuse of select factory sensors)
  • Use Case: Performance towing, daily driving, and off-road
  • Regulatory Note: This product is intended for off-road use and does not currently carry a C.A.R.B. sticker.

Installation Pro-Tip

Before you begin bolt-on installation, disconnect the NEGATIVE GROUND CABLE from your battery. This allows your truck's ECU to reset and recalibrate for the increased airflow and cooler temperatures immediately upon restart. Always ensure the engine is cool before working.

Ready to let your Duramax breathe? Upgrade your intake today and feel the difference.

Engine Safety Rating
Difficulty 

Fitment

Make

ChevroletGMC

Engine Size
  • 6.6L

Year
  • 2004
  • 2005

Installation & Tools

The Wrench Time

  • Estimated Time: 45-60 Minutes
  • Difficulty: 3/10 - Basic hand tools and a straightforward bolt-on process, but requires a delicate touch with engine sensors.

Tools You Will Need

  • 10mm socket, extension, and ratchet (Battery terminals and factory airbox tray)
  • 8mm socket or 5/16" nut driver (Hose clamps)
  • T20 Torx bit (MAF sensor removal)
  • Panel popper tool or flathead screwdriver (Wire harness clips)
Mechanic’s Pro Tip (The "Gotcha"):
The 2004-2005 LLY Duramax is notorious on the enthusiast forums for its restrictive factory turbo mouthpiece and extremely sensitive Mass Air Flow (MAF) sensor. When swapping to this cold air intake to help lower your EGTs and let the LLY breathe, you MUST handle the MAF sensor like glass. Dropping it on the driveway is an instant $150 mistake. Furthermore, when transferring the MAF to the new aftermarket intake tube, do not over-torque the screws or you will strip the new housing. Snug is safe.

Phase 1: Removing the Factory Part

  1. Disconnect the Battery: Always start by disconnecting both negative battery terminals on your 2004-2005 Chevrolet GMC Silverado Sierra 6.6L using a 10mm wrench to prevent accidental shorts and check engine lights.
  2. Unplug the MAF Sensor: Slide the red locking tab back, press the release clip, and unplug the wiring harness from the factory MAF sensor. Use a panel popper to carefully detach any brittle plastic wire loom clips attached to the factory intake tube.
  3. Loosen the Clamps: Use your 8mm socket to loosen the factory hose clamp securing the intake tube to the turbo mouthpiece.
  4. Extract the Factory Airbox: Firmly grab the factory airbox and pull straight up. It is held in place by rubber grommets that often become stiff and dry-rotted from engine heat; a solid, straight yank will pop it loose without breaking the mounting pegs. Remove the entire tube and box assembly.
  5. Remove the Airbox Tray: Grab your 10mm socket and remove the bolts holding the factory metal airbox mounting tray to the fender well. Keep this hardware handy, as you will reuse it for the new heat shield.

Phase 2: Installing the Cold Air Intake

  1. Transfer the MAF Sensor: Using your T20 Torx bit, carefully remove the two screws holding the MAF sensor in the factory tube. Gently pull the sensor straight out and install it into the new aftermarket intake tube using the supplied hardware. Remember the Gotcha: do not over-tighten!
  2. Mount the Heat Shield: Drop the new aftermarket airbox or heat shield into the engine bay. Secure it to the fender using the factory tray bolts and your 10mm socket.
  3. Install the Silicone Coupler: Slide the provided silicone coupler over the factory turbo mouthpiece. Slide two hose clamps onto the coupler, but only snug down the mouthpiece side with your 8mm socket. Leave the other loose for final adjustment.
  4. Position the Intake Tube and Filter: Guide the new intake tube through the heat shield and slide it into the silicone coupler. Drop the high-flow air filter into the box and attach it to the end of the tube. Once everything is aligned, tighten all hose clamps securely with the 8mm socket.
  5. Reconnect and Calibrate: Plug the MAF sensor harness back in and firmly press down the red locking tab. Reconnect both negative battery terminals with the 10mm wrench. On the very first startup, do not touch the gas pedal for 20 seconds. The ECU requires this idle time to safely adjust fuel trims for the massive increase in airflow.

Disclaimer: This is a general guide provided for the 2004-2005 Chevrolet GMC Silverado Sierra 6.6L. Always refer to your factory service manual for exact torque specifications and safety procedures.

Warranty

All products are backed by our Limited Lifetime Warranty. We stand by our quality. [See terms]
Cold Air Intake for GMC Sierra Chevy Silverado 2500HD 3500 (2004-2005) 6.6L V8 Diesel Engine

$139.99