unresponsive throttle

04-350-6.0-170K-100% stock Has had an intermitent what feels like a miss for 16 mos. 1st dealership trip replaced EGR,EGR cooler, oil cooler, couple of injectors. Dealership trips 2-6 replaced EGR 2 more times and reprogrammed/updated the computer. Tried another dealer for trip 7 and only...