My car runs good at 100 MPH but at 35 it bucks and misses bad. I changed the spark plugs and fuel filter with no change. I put the spare icm w/paste and now the teach is all over the place. It always worked fine . My cap is not that old and my wires checked out OK. When it runs it sounds like a sewing machine. A sound I have never heard from the engine before. Bad something having to do with fuel? Help please
Tach filter has nothing to do with how it runs, only what the tach reads. Double check timing, fuel pressure, check for clean intake tract (throttle body, etc.), clean IAC, proper O2 sensor operation, and verify no check engine light.