0xygen Sensor....HELP

[Bob Mansker <oscargum@datasync.com>]

Doing my Sunday ritual by trying to make the Audi gods mad at me.
I have a 87 5KQ 2.3 (Non-Turbo)
Trying to take voltage readings on the Oxygen Sensor.
Have (3) wires from the sensor.... White, White, & Black.
The Black is the one.
As the engine idled (hot) I get readings from less than 100mv to 750mv.
(moves between these 2 readings as it idles.)
Introduced Propane into intake air chamber with no rise of voltage readings,
didn't cahange at all.
Opened up a vacum leak with same results, voltage went from 100mv to 750mv
even with a vacum leak hissing away.
I heard that you can pull out the sensor & heat it up with a propane torch &
this may fix it.
Can anyone Help me on this?
Thanks,
Bob