As shocking as it
seems, at some point you are going to have to get under the vehicle and look around for things like this.
If the vehicle has never had the O2 sensors replaced, I would do that first. The code is for the passenger side O2 sensor reading after the cat, BUT if the sensor before the cat is fouled, that can throw off the fuel mix ratio and then the cat can only scrub so much so the downstream O2 sensor could be functioning fine and just reading out of range due to the upstream sensor failing, but given the age of the vehicle, I don't feel like it's shotgunning the repair as much as an inevitable part(s) replacement (instead of proper diagnosis) to replace all 3 O2 sensors since they are likely near end of life anyway, then clear codes and see if they come back.
If you really want to be minimal (labor and cost) about it, I would replace the upstream sensor before the cats first and clear the code, drive a while then see if you still get the code.