DiabloSport knows diesels- the U7185 Predator handheld tuner for 2004.5-2005 6.6L LLY Duramax Diesel trucks proves it by supplying users with the features, power, and economy to suite their needs! Featuring 4 pavement pealing tuning levels (40 HP, 60 HP, 85 HP, and 120 HP) this tuner brings your truck to life while towing heavy loads, or just cruising on the highway! If you've got oversized or non-stock gears no problem- The U7185 allows users to adjust gear and tire size as well as raising the top speed limiter and it checks and clears diagnostic trouble codes!