2001 Subaru Legacy 6 cyl Four Wheel Drive Automatic 53,000 miles. By mistake my daughter put high octane fuel in the car. I've always used the lowest octane. Maybe it's a coincidence, but right after that (the same day) the "check engine" light came on. Could the change in fuel have something to do with the light coming on? The car seems to be running perfectly. I don't have an appointment at the dealer until next week. Is it safe to drive the car until then?
The check engine light goes on for a number of things. It could have picked up a different reading from changing the octane. If you hear anything unusual or see anything unusual, then I wouldn't drive it until the appointment.