The filter is built into the fuel pump/gauge unit which is installed into the top of the tank. I suspect water in the tank and the best way to check for this is drop the tank (not real hard to do), remove the pump unit and look inside. If water does get past the filter and get into the fuel injection system you will have real problems so don't take this lightly. I don't know of a "typical" problem in these cars to cause your complaint but it soulds like water in the gas to me. Does the problem resolve itself if you take tha gas cap off? Try it, the cap may be defective allowing vacuum to build in the tank as fuel is used up. If you hear a huge sucking sound when you take the cap off you may have found your problem.