About two weeks ago, my check engine light came on and after half an hour of driving, it turned itself off, so I thought nothing of it. Come today and it comes back on out of nowhere after driving home from school for, like, 5 minutes. Immediately going straight to AutoZone to get an OBD test and 19 different codes came up (9 codes came up twice). From all 6 cylinders misfiring, O2 sensor going bad, ABS problems, but its been driving the same as it always has. Driving back home, in the parking lot, the light turns off. What's going on?