Honda Repair: 99 Honda Civic CX Malfunction Indicator Light, honda civic cx, malfunction indicator light

Question
Bill-
  Five days ago my malfunction indicator light in my 1999 Honda Civic Cx came on as I was leaving work. I read in the manual that it could be a loose gas cap so I tightened the gas cap hoping that would fix it. After three trips, the light was still on so I took it to Auto Zone to have them run a diagnostic test on it. The test showed that the oxygen sensor was bad so I bought the sensor and had it installed yesterday. I have made four driving trips since then averaging fifteen miles each trip. The light is still on. Should I go back to Auto Zone and have them run another test?  When we took the oxygen sensor off we could see that it had been taped up by the previous owner and was in bad shape. I don't want to do any damage to my car. Any advice would be appreciated. - Keri  

Answer
Kerri:
There are two oxygen sensors on your car so either one could be bad or neither one. Be careful when you read those codes as the code only reports a problem with a sensor and not a diagnosis of the problem. You may have a lean or rich running condition causing the O2 to show a malfunction. Another problem with O2 sensors are that sometimes you have to buy an OEM (Honda) part.
Hope this helps.
Bill