My 2005 CLK 500 check engine light came on yesterday. Could smell strong gas oder. Took it to dealer and they stated it was the fuel pump. Repair will cost $1200 plus. This car has cost me a lot of money. Just last week they told me the radio going out was a bad amplifier. Think twice before buying this model. It leaked oil when i drove it home the day i bought it new. Oil pan gasket pinched. I bought a lemon. My car is 9 years old and only 69k miles
It means the onboard computer sees a problem with many differant possiblities. Usally a emission standard issue. If you have a shop you deal with for service that would where I would recommend you take it first. If you don't know where to take it get recommendations from coworkers, or friends.