So while coasting in gear, my car, a 99 sl1, starts to kind of feel like it's misfiring. if I tap the gas, it will stop, and I can conitinue to coast, until it does it again in a few more moments. Someone said that this could be from a faulty Catalytic Converter - is this true? just gave the thing a tune up hoping that was the problem.
I haven't replaced the fuel filter; could this be it?
What else? Any help is appreciated!