Duramax diesels thrive on traditional performance modifications such as improved intake, fuel, and exhaust systems. A good starting point is to replace the restrictive OE intake resonator, factory airbox, and intake system with the high-flow-capacity Fuel Injection Performance Kit (FIPK) intake system from K&N ($340). C.A.R.B. approved and 50-state legal, these kits are backed by K&N's Million-Mile Warranty. K&N; 800/213-4182 (dealer info).
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