Let's see... I hardly give out tech advice. I prefer for people to think I am clueless.
I know you have been fighting this one, so I'll give it a shot.
I believe there is an upstream and downsteam 02 sensor. Upstream being before the cat and downstream being behind the cat. The code should indicate which one if faulted. They are not expensive though, and easy to replace. A 7/8 wrench will loosen it up for removal, then you clip the wires. Connect the wires for the new one, and tighten it back in.
Also, I am fairly certain that there is a fuse on the fuse block under the hood that is used for the 02 sensor circuit. Check it out, too.
Let me know if this helps you any.