My check engine light has been coming on. I took it to an auto parts store and they scanned it and said it was a misfire in cyl 6. Then all of a sudden my light went off. They didn’t reset it. I turned the car off and the light was on and when I started the car again it was off. what would make it go on and off without it being cleared?
It’s not MISFIRING bad enough, yet. It could still be damaging your catalytic converter from the unburned fuel sent to it each time the engine misfires. You haven’t given any information about the car, or the engine: type, total miles, v-6, 4 cylinder. Minimal stuff: change #6 spark plug. If still a light comes on, change #6 spark plug wire. If still a light comes, get a mechanic.
If this problem is with the explorer from your earlier question the misfire on cylinder 6 could be an indication of what is happening to your coolant. If the coolant is leaking into cylinder 6 it could create a misfire that might come and go. You need to have the spark plug pulled and checked for antifreeze residue.