Originally Posted By Supercuda
Those TPS sensors have a rep for getting "dirty" at the idle position. With it hooked up and you monitoring the data, slowly open and close the sensor, it should sweep smoothly with no jumping around of the data.


Well, my replacement throttle position sensor arrived and you're right:



Slightly odd way to fail but apparently the old sensor didn't properly return to idle.
I'll check the MAP sensor with a Mightyvac next, just in case.