if you're able to scan it, then watch what the O2 is actually doing before swapping it. sure, it's cheap and can be a PITA to swap, but i'd still check how it's working. that's just me. currently i don't have money that i can just throw at parts, so i'd verify before i swapped. don't know if you know what to look for but...... if your "scan tool" reads either "rich" or "lean" for awhile, like it's stuck, then i'd take a voltmeter and read the sensor output. (unless your scan tool already does it). watch the volt reading. it should be between .1 and .9. if it's outside that range, it's bad. if the voltage is not moving around like a rabid cat in a dog pound, up n down within the range, it's bad also. it needs to be moving cause the ecm is constantly adjusting the AFR. that's normal.
hope it helps. but if you got the moolah, then just ignore what ihave just posted.