2002 check engine light?

Question

it reads everthing is ok have already changed oxygen sincer this is what it read first the light is back on Geo tracker 2002

Answer 1

If the reason the service engine light was on was the O2 sensor and you changed it then you have to reset the computer.
It may be a computer but it is not as smart as you think.
When the computer gets a signal from all the parts it keeps the light off. When a bad part sends a signal telling the computer it is bad, it turns on the light.
But even changing the part the computer still things the old one is there and will not keep the light off until you reset the computer.

Answer 2

Try disconnecting the battery for 5 to 10 minutes to reset the computer and clear its errors. If the light comes on again, check your codes again. Also, some cars have more than one oxygen sensor.

Answer 3

have u checked the gas cap? i know it sounds funny but when my check engine light came on it was because my gas cap was broken and it wasn't making a complete seal once i replaced it the light turned off. Another thing might be if u have already replaced something the car might need to be reset just un hook the battery for 15 mins and see if that works.