Went down today and got a flashpaq and tried to install it on my "09 GMC LMM (i think that is the right letters for this truck) and it would not take.? returned to store and they downloaded another new one off superchips web site and tried to put that one in and still will not take?? 1, is this flashpaq what I need to be using, 2, is it compatible they say it is? 3, is it a must to remove the DPF? Thanks for any help with this.. Jon ,,, Just trying to get a little better performance..