Good day all or good night ,,,,,I've recently purchase a used 2002 C230 Komp.....Twice now that i've got the warning that my gaz cap is not close properly . Both time i stoped and check and both time it was properly lock in place. After two warning i get a Check engine light in dashboard.......any clue or what i should do???

tks for all you time and concern..

 

Did you check the tank purge valve and pressure switch?