I just purchased a 97 C230 with 94,000 miles on it. The first thing I did was to replace the air filter. Today I replaced the fuel filter. It is located under the car in front of the passenger side rear wheel. To get to it you have to remove a plastic cover (3 10mm nuts). Remove the clamps on both ends of the filter and loosen the big clamp that holds the filter in place and pull it out. I loosened the gasoline cap to releave the pressure in the tank. Still some gasoline will run out of both ends, but not much. I used a small pan to catch the fuel. Put in the new filter and tighten everything back up and you are good to go. The filter cost about $25. I used a Bosch filter. This is a do it your self job.