Check engine light comes on - Dealer pulls code and tells me that it is the O2 Sensor. They check it out - do some fix, clear the code, give me the car back and about a week later, the Check Engine light comes on again. Take it back to the dealer and it's the O2 senor again.

Check Engine light on again the night before I had a scheduled maintenance appointment scheduled. Dealer called when car was in shop - said it was the O2 Sensor again. They have no solution, so they cleared the issue and gave me the car back. Check engine light back on two days later.