I posed this question on my Fabspeed thread, but decided to start a new one. I used some WD-40 to help me remove my O2 sensors. If I got some of this on the sensor side, will it wreck my sensor? I have one that I am not sure about and am wondering if I should clean it with something like acetone or lighter fluid prior to reinstalling.

Most likely a lightweight oil like WD-40 will burn off rather quickly. It is things like anti-seize that is more of a concern. I'd say you're good to go.