Does the Check Engine light have to be reset after the problem is fixed? Or does it automatically reset?
for example, some idiot starts his car without plugging his 02 sensor back in, and the CEL comes on. then he plugs in the 02 sensor, but the light comes back on again when he restarts the car.

I'm gonna go to AutoZone for a free diagnostic checkup so I can get what code it's throwing in case it's anything else...but I doubt it.

 

I know on the OBD-II you can retrieve codes even after the light goes out. I am not sure about the OBD-I. But the light will go off once the problem is fixed.