That was the theory of the tech at the dealership - that crud in the TB was messing with the TPS's mind, although he admitted he was only making an educated guess.
I've never cleaned the TB myself, so I'm not sure if the dealership has some special technique, or that when they're messing around in there they accidentally reset something else back to where it should be. (I wonder if that could be the case, because in one early attempt to correct the problem, they made a mechanical adjustment to the throttle stop - or something like that. That worked, but only for a couple of weeks.)
I've talked with the techs at length, and they're quite candid in admitting that they really have no idea what the problem is.
In any case, the TB cleaning is the only thing that seems to work for any length of time on my car when it starts doing the high idle thing.
