2004.5 - 2005 GM 6.6L LLY Duramax | Engine Tuning by PPEI

Gain 120+ HP over stock, tow your toys effortlessly, and rapidly increase acceleration. Tuning engineered for optimal efficiency and the best potential fuel economy! STOCK TRANS Level 1: +15 HP Level 2: +30 HP Level 3: +60 HP Level 4: +100 HP Level 5: +120 HP BUILT TRANS Level 1: +30 HP Level 2: +60 HP Level 3: +100 HP Level 4: +160 HP Level 5: +230 HP This tuning package can be installed using an EFILive AutoCal V2, FlashScan V2, or AutoCal V3.