Just another thought on the C5.This fault has shown three times and cleared on my many road tests,P1622 throttle motor position sensor/manifold absolute pressure sensor -correlation. I do see very strange readings from the pedal position sensor (at the end of acc. cable).When I hold the pedal in the same position with the fault apparent,normally going up a hill, the readings stay around what I normally see at idle.The power does return on and off and the reading rises sharply with this.I have replaced the pedal position sensor but no improvement.Any ideas ...?