Hello, i have Mercedes C230K the Engine Light comes up after about 30 miles of a full gas tank and goes off after less then half of a gas tank. Any Ideas?? Thanks.

 

Hi,
USA or UK spec vehicle? You say "gas" so I guess its USA.

Full tank? How full? To the point the auto pump shuts off or "brim" full?

Has it done this cycle more than once or did it come on after filling and went off at half full and has not reoccurred?

Just as a passing low cost idea have you checked that the gasket on the gas cap is in good condition. Any smell of fuel?

Mileage / Age of vehicle?

Have you ever had the "Check Engine" light on previously? Might be nothing to do with fuelling subject to questions above.

Stuart