Duty cycles all over the place

The duty cycles on one my E's is all across the board. It'll jump from 33% to 65% to 100% to 0%. It's running all over the place with regard to frequency as well. Apparently it's supposed to run at 100 hertz, but it too is all over the place, registering even into the khz. When I unplug the O2 sensor it registers a solid 85% and 100hz., (I believe the appropriate trouble code). My other E is fine (43% +/- 10%), so I'm pretty sure the multi meter works and my setup is correct. The O2 sensor puts out between .1 and .9 volts and responds rapidly.

Thanks,
Robert

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89 300te 222,222
92 300e 190,000