Well so much for the nay sayers,Superchips rock! Got my tuner (2865)today.I updated and installed the tune with no problems.I have a 2009 1500 Silverado with a 5.3. I have a Gibson cat-back and a Volant cai . I programed the Active Fuel Management OUT. The sound of the exhaust was terrible when the AFM kicked in and out.(V8-V4-V8-ect..).The tuner also adjusted the shift pressurers.I used stock +8 % on the 1-2 shift,2-3shift and stock + 6 % on the 3-4 shift. The truck runs MUCH BETTER.So anyway I say Thanks to SuperChips for a product that works as advertised..