cruising along on the highway 60mph or so with about 5psi of boost and the truck laoded doesnt matter if it is a trailor and all in the bed. When I start to go up a hill the truck doesnt down shift and the boost will rise to about 20 and then it will miss. Almost like a throttle positioner lost where it was. It is a very noticealbe loss in speed. Took it to a ford delership and the guys rode in the truck with it loaded and they got to see how it was missing. Had a scannor hooked up during the ride. Nothing showed up so they say that nothing is wrong with the truck.... is any one else having this problem or could help?