How to clean and/or check o2 sensor?

Does anybody know if there is a good way to clean an o2 sensor, and to test it with like an ohm meter to see if it's good??

As far as I know cleaning it won't help, however it can be checked

Check here (http://www.binghamtonlife.com/manual/2gsm/images/91-11-36.jpg)



and here (http://www.binghamtonlife.com/manual/2gsm/images/91-11-37.jpg)

GL