I have a 2002 Civic Si, the chassis has approximately 90k on it, with a motor that is in the mid 40's. Recently my car started to expirience a sputter or backfire while holding speed on the freeway. I checked the plugs and they appeared to be fouled with oil, so I replaced them and got new valve cover gaskets to go along to change any chance of it happening again. It seemed to work, for about a week, but it came back. It has now gotten to the point where I don't want to drive the car, as I don't want to make the problem worse. It is also now doing it under acceleration, not just while cruising. I have exchanged the following parts from a known working car; coil packs, map sensor, fuel pump/filter, fuel injectors, fuel rail, throttle body, main relay 1 and 2, ECM and intake manifold has been cleaned, air filter is in good condition. There are no codes on the ECU. No cat-converter is on the car. Yet the problem persists. I do not know what else I can change to get it to go away.
Monday, May 8th, 2006 AT 11:34 AM