tracking down a failed smog test so I tested the EGR stepper motor. Procedure was given but it didn't really tell you how far the pintle moved per shorting of 2 pins. It moves about .002! Short the pins in sequence and the stepper motor will move, short the other direction and it will move the other way. I found my EGR was functional, clear of any blockage and I still have high NOx on my test...whats next... New cats?