Urq sorting out

[DGraber460@aol.com]

Took Huw's advice and monitored the O2 sensor voltage.
At cold start, had .646 to .650. 
At 3 min. had      .616 to 655  The DC read 49.6 at this point.
Blip throttle =   .555 to .594  DC still 49.6 (steady)
Lean 3mm screw 1/16 turn = .158 to .173 DC steady 49.7
blip throttle =       .130 to .159      DC steady 49.7
Took it down the block and rechecked;
O2 sensor voltage = .104 to .120        DC at 49.6
Grounding (0 ohms) or disconnecting altogether (infinite ohms) the temp 
sender has no affect. The sender registers 90 ohm's when hot, and I have good 
continuity to the ECU.
About the time I think I've found it, a double check of the component shows 
otherwise. I still feel that I'm close. Does the O2 sensor look suspect? Both 
units I have give the same result. TIA

Dennis