[Maroon 5.0 LX]

A loose or defective gas cap WILL cause the check engine lite to come on, but should reset the codes in a short time after the system is sealed.

You should have the dealer run the codes and repair as necessary. It could very well be something very simple. Request them to make sure the car meets all factory emission requirements, even if your area does not require emissions tests. You should also request a copy of the read-out for your records.

Good luck with your new car!