2008 Toyota Solara oxygen sensors

Oxygen sensors keep going out on my 2008 Toyota Solara (50K miles). Is this a common problem with this vehicle? Dealer says running the car with the check engine light on hurts gas mileage and may harm the catalytic converter. True or not?


I don’t see anything where all these cars fail O2 sensors any more than any other car.

Who diagnosed the oxygen sensor and was there a code thrown at the time.
If there was a code…what was the code?