I just got my truck back form the dealer for the same problem that you are describing. This sounds like a timing problem on the injection pump and that would throw the 0216 code.
You can check your fuel pressure at WOT , but I would be willing to bet that when your pedal goes dead that the fuel pressure doesn't drop.
I have 88,000 miles on my 02 and the loss of power problem I was having when on for a couple of months. If this is an injection pump timing failure, chances are that the problem will be intermittant. I only saw the problem after cruising at highway speeds for a period of time.
If this is an injection pump failure, it is covered under warranty for 100,000 miles, but the dealer will have to get the truck to reproduce the failure. This proved to be difficult for me. I had to drive the truck for another 3 weeks before I could the truck to fail when I was close to a dealer.