Hi, I need some help..I have a 2000 C-230 Kompressor. I bought the car used with 60,000 miles, ran great. But unfortunately I let the fuel filter go to 125,000. One day while driving on the highway it backfired a little bit and then started to sputter.

I figured immediately it was the fuel injector.

I changed the fuel filter which only helped a little bit, then I started using Lucas fuel cleaner which didn't do much, then I tried small amounts of transmission fluid which helped maybe a little.

The car still has power and is good at high speeds ( 60+mph ) although I can still hear a slight sputter which comes back when stopped.

I went to AutoZone and they hooked the car up to a computer and told me the number #1 cylinder was misfiring. I think it is a fuel injector since I've changed the spark plugs.

Any help is appreciated.