My IAC does click very often, more so than any other vehicle I have, but it only caused an idle problem when it was dirty. I also notice a click or two some minutes after I turn the vehicle off which I always assumed was the emissions canister solenoid and never investigated further since it did not affect use of the vehicle.
I would just ignore the click for now and get back to it if it seems related to a problem. It doesn't seem at all related to an O2 sensor failure. I was going to suggest that you could spray more cleaner in the intake in case there was just too much gunk cleaned off at once that fouled the sensor, and that more might get it clean again, but if you did that and it fouled yet another sensor... don't want to be responsible for that. Some people put seafoam through their intake and swear it helps, but then every now and then you come across someone who claims it fouled a sensor or their cat converter.
This is an area where I feel like vehicle service records help. The IAC does need cleaned or replaced every few 10's of thousands of miles (depends on driving habits, many more miles from highway driving than short trips), like a regular maintenance item. If it has not been done on yours, then it probably needs done but there are too many variables for me to state with confidence that doing so will resolve your problem, and not likely to solve an O2 sensor code.