I've only ever seen the throttle pedals on these fail to cause lack of acceleration, ie car will start, but only run on idle.

Inside the throttle pedal you have 2 sliding potentiometers (APP1 & APP2) basically one sensor goes from 0-5v the other goes 5-0v depending on throttle position and the outputs are worked out by the PCM to give the true pedal postion..

They do this to stop there being any chance of a 'run-away' situation where the engine can rev on it's own.

If any of the APP sensors fail the PCM will only allow a certain amount of torque to be produced, as I say, usually if the pedal fails it will only allow idle speed.

Happy to be proved wrong of course.