As mentioned above; the code will be saved in memory. So keep your scheduled appoinment and get it checked.
Good luck

 

what was the outcome of this problem?

 

I know this is an old post but another thing to check is make sure your gas cap is on tight this will bring a code/engine light on showing as an 02 sensor. I have had this many times happen on my 03 tj. I never replaced any sensors just mcgarver taped over the light until it goes out (its not a repair its a quick fix)