Ok, I will see if I can figure it out... I'm just a self taught mechanic and learning as I go. I do tend to catch on to things quickly though so I'll see if I can figure out where these things you mentioned are.
Check the pedal position potentiometer, calibrate to center ,if it was replaced it has to be calibrated , if not probly needs to be replaced an calibrate. Also check wiring running under pedal assy ,I've seen the harness run thru an create shorts , also check the pedal pot gear is not worn out an going out of range.
231 Combination of pedal position sensor signal and reference sensor signal is not plausible.