Accelerator Pedal Position Sensor

I have a '00 with about 72,000 miles. This weekend the Accelerator Pedal Position sensor went up and I limped it to the dealer. It is a hefty fee for replacement and very frustrating.

I saw other threads on this board cautioning about the Throttle Position Sensor as well. The dealer is insisting that the APP died due to gunk and carbon in the throttle body, and that the TPS is ok. Could build up truly be the cause? Will fuel grades cause this problem? I bought it used, so I don't know what the prior owners put in it.

I plan on driving this vehicle until it is very old, grey and dead, so I don't want to run into this expensive problem again.

I don’t think the gas has anything to do with the failure. The gunk is caused by the EGR. Mine threw a code that was related to the gunk (you could search my name for the code #), so cleaning it certainly wont hurt.
What code did yours throw?
DMX

Do you know the specific problem code?