Not reaqding O2 Sensor #2

My daughter's 03, 2.2 engine code is saying it cannot read O2 sensor #2. The car runs perfectly fine, so I am telling her to ignore it as she plan to trade for a new(er) one soon. Is any damage being done to the engine, or anything else to be worried about by not getting this looked at?
Thanks.

#2 O2 is for CAT, maybe it is disconnected or damaged. Nothing will happen to her engine.

Thank you!