Check engine light turned off by itself?
 

Hi. Last week my wife's car had Trouble code: p2626 '05 Elantra, that is for the front O2 sensor. We scheduled an appointment for possible repairs to be performed tomorrow. While she was driving to work today the CEL turned off. NOW WHAT? Cancel the appointment? or proceed as though there is still a problem? Thanks, Angelo.

Keep the appointment.

Thanks again NovaSource!