Hello guys...i'm new to the forum and would like some much needed help. i have a 03 E320. yesterday it went into like a "safe mode" and would not go over 30 miles an hour. the check engine light came on and so i just coasted on home. checked it out and it had a error code P0456 and multipule misfire codes on the cylinders. talked to a guy at the dealership and he's saying its possibly the gas cap. are there any other possible reasons for this to happen?
im thinking he may just want to get me into the dealership for some outrageouse charge.
thanks