Did your buddy return his truck back to stock with the 9100? If not then you can't use it. If he did return it to stock and your truck is a pre-2004 then you can use it, but I believe it has to be set up for your PCM before doing so. You could probably just order a new one with 3 custom tunes from Troyer for just about the same price. Personally I would just hold out and get the Xcal II and Troyer custom tunes. Plus by going with the Xcal II and Troyer custom tunes you won't have to worry about making any user adjustments, Mike's custom tunes are 99.9% spot on right out of the box. You won't be disappointed.