I have a 2005 lly 2500hd cc sb. Yesterday I replaced my Fuel pressure regulator and changed it to a lbz fuel pressure regulator along with reflashing my efi live tunes with new tunes for the lbz fpr from calibrated power. To start with it seemed like the truck had an electrical issue this morning, stud #1 fuse was blown under the dash changed that out and truck would not start, no power windows, no interior lights, locks, etc.. Disconnected the batteries let them reset. Driver side battery was only reading around 9v so let that charge and started the truck. So at this point everything seemed back to normal, everything in the truck was working, batteries are reading over 14v. So I decide to go for a ride up and down the road a few times, seems okay until i hit about 45-50, assuming this is where the truck goes into overdrive, and then it starts bucking. If i let off the throttle it smooths out but when applying throttle the bucking comes back, if I lay into it the bucking seems to go away. Anybody have any ideas? Its been a long 24 hours dealing with these issues Id really appreciate some input, thanks.