One problem related to o2 sensor has been reported for the 2002 Ford Focus. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2002 Ford Focus based on all problems reported for the 2002 Focus.
I have only owned this car for four months. First the oxygen sensor failed after two days. Then a month later I began having different lights come off and on with loss of power. I took it in to dealership and to Ford who could never repeat the codes. I replace the battery and this stopped for a month. It is now doing the same thing again. Stalling or acting as if it will. I have to pull over and restart it several times to reset the computer to get it to drive correctly. I am frustrated because no one can find out what is wrong. This occurs intermittently but when it does it can be over 10 times a day.