thanks for the tip on the Bosch sensor... I will go OEM or go home.

now for the money question...

can anyone give me some instructions on how to verify that it IS in fact a bad sensor, and not a wiring issue external to the O2 sensor itself?

and I followed those wires back a ways, and they disappear into the underside of the car through a rubber grommit before hitting any connectors that I could see...

thanks in advance.