The Power Pup Downloader is for those looking for more power for towing and performance, or for the extreme driver looking to decrease their time in the quarter mile. The Power Pup increases horsepower and torque be re-flashing the vehicles Engine Control Unit (ECU). Installation takes place in-cab by plugging the Power Pup into the OBDII port. The Power Pup gives the user the choice between four different power programs: Stock, 50, 75, 95 or for an additonal fee there is an extreme 150 hp. The Power Pup retains the stock program so that the truck can be put back to the original settings if the need arises. The Power Pup will also allow users to remove the speed limiter and also contains the ability to adjust for tire size, raise the rev limiter and checks as well as erases trouble codes. This Power Pup Downloader works on the LB7 engine. Not Recommend to put put on 4500 models and above. Engine Identification Information The 8th digit of the vin # on the LB7 engine is a 1 The 8th digit of the vin # on the LLY engine is a 2 Features & details For '01-'04 GM Duramax LB7 + 95 HP/180 lbs.-ft Highest horsepower of any downloader Increase in fuel mileage Internet upgrades