hi all new to the site. I have a 2001 Chevy k2500hd with an 8.1 170,000 miles. At low rpm and slight accelerator pressure the engine acts like it is misfiring and sometimes at heavy acceleration the truck seems to backfire through throttle body. Could this have something to do with the drive by wire on the tac. Truck also has the Allison Trans. Thank you any input would be greatly appreciated