Was easy to use, hooked up on 2011 Chevrolet Silverado 3500 with 6.6l LML duramax. My truck was in limp mode already with a problem in the DEF system. The programmer just took me thru the steps and I just wanted to delete the DEF anyway and it was simple. Cost of going to the dealership was going to be the same price. The only problem I guess I have is that I don't have shift on the fly power levels. Don't matter I just wanted to drive my truck out of limp mode and now I can choose to go up in power if and when I want to.