Video on how to check oxygen sensor to see if it's bad 1998 mercury mystique ls.

I have a code reading P1131 bank 1,I think this is o2 sensor before the cat.? If I'm wright, what's the best way to get to it, and when there,can I check with ohm meter,continuity,or what? What's the reading #s? Is there a video on this, I could use a show and tell, if available?

Thanks!