Hi everyone. I have a 04.5 3500 with auto. I was running a smarty on level 4 for several years with absolutely no trouble, towed my gooseneck great with absolutely no problem. Well i got hp tuners for ls swaps that i do and decided i would have firepunk write me some tunes for my truck. so i created a new file for my truck and went thru the process. Loaded my firepunk tune and the truck runs great without the trailer, hook the trailer to it and start pulling a long grade and it goes into limp mode and drops back to 55mph before it will kick back in. I believe its limiting the rail pressure. I read something about the updated calibration doing this. question is, whats the way around it or is there a way to go back to the old calibration. any help would be greatly appreiciated.