Ford: check engine light, o2 sensor, countour

Question
I have a 98 countour SE, V6, 2.5L.  My check engine light came on a few months ago but the car seemed to be running fine.  I had the light checked at autozone and they said something about a bad O2 sensor.  Does this need to be looked into further, or should I just reset the light myself(I know about disconnecting the battery...)?  Also, recently the car had trouble starting (after sitting outside in the cold w/o being driven for a week).  No problems since, any relation to the check engine light?  Thanks, Linda

Answer
Linda,
If your 02 sensor is bad, then it will need to be changed. Driving with the lite on is okay for now but service is needed on the vehicle. If you try to reset the lite, the lite will come back on. Also, you will have a bad idle problem if the 02 sensor isnt changed... Thanks.. and Happy New Year..