You MAY have found the problem Jerod. I did a search and came up with this page that tells you how to test the TPS, how it works and how to replace it.
http://members.fortunecity.com/slade...iagnostics.htm It appears to be a "generic" piece of information that applies to most all units, not just ones on Fords.
But now, the bad news:
My Haynes manual says the TPS is not removable on 2004 4.6L or 5.4L V8 models. To replace the TPS on these models, you have to replace the electronic throttle body assembly. So, curing the hesitation, if caused by the TPS, might be a bit of a major operation.
I'd sure try to test the voltage output of the thing first (if possible). As the sensor moves from the closed to open position, you want a smooth increase in voltage, with no spikes or drops.
I hope someone else has another thought that might be an easier, and presumably, less expensive route!
- Jack