>| Did your application of 1.5v and 0v cause the engine running to change?  I
>| know you saw no effect on the sensor...

	Nothing I could perceive really - no voltage change across the O2
sensor, nor a dip or surge in the sound...

	I just found my old variable DC converter from some old physics
project, so maybe I will try and hook it up and watch if the voltage
across the O2 sensor flucates at all when I twist the knob - the display
on my multimeter should flicker or disappear if it cannot lock on to a
voltage...

dave