Cold air intake systems aren't created equal and savvy customers know it. This is why Volant Intakes are so popular with customers who know their air intakes. What makes Volant Cold Air Intakes different? First, Volant eliminates your restrictive factory airbox, filter, and intake tube. In its place goes the Volant Power Box. This box houses a high flow Volant PowerCore Air Filter that is dry and maintenance free for 100,000 miles. This revolutionary air filter does not require any oiling and offers superior filtration. The superior design of the Volant Intake Box protects the filter and ensures that colder air is pulled in from the fender instead of the engine bay, resulting in more horsepower and torque. Being an enclosed system, it keeps your engine quiet at cruising speeds, but allows it to still roar to life when you stomp the gas. This, coupled with the fact that Volant Cold Air Intakes incorporate your existing sensors, mean you won't have any check engine lights and they are safe for use on your vehicle. This "Factory Tuned" design means you won't need any tuning and makes this truly a bolt on system. Everything you need to install the unit comes with your Volant Cold Air Intake and you'll be able to install it with basic hand tools in an hour or less. Volant Intakes all are backed by a lifetime warranty. Volant Cold Air Intake Systems exceed OE standards and as a result will not void any existing factory warranties that you may have. Additionally, you'll enjoy increased horsepower and torque, as well as improved throttle response. Fuel economy gains, especially during freeway conditions, are commonly achieved helping the unit to pay for itself over time. The part number for this item is 159666 and it fits Mid 2004-Mid2005 Chevy Silverado GMC Sierra Duramax Diesel LLY 6.6 models. This Volant intake is 50 state legal. It is covered by CARB Exemption Number (also known as an EO Number): D-526-3 . If an emissions inspection facility ever questions the legality of this Volant Cold Air Intake System, you can provide them with the CARB EO Number above.