My wife had the CEL come on this morning. She drove to a class about ten miles away, came out 90 minutes later and the light came on upon starting and stayed on.

I removed and replaced gas cap securely. No change.

She is at 40,800 miles, and 8,200 since last service. OBC says 68 days till service.

Coincidently, or not, yesterday i topped up the oil with M1 0-40 euro formula oil. It was near the bottom of dipstick, and is now just barely below the full line.

Any suggestions other than a trip to the dealer?

TIA.
David in MD