I need some direction on this one. So far, I've changed the spark-plug and the COP, cleaned the throttle body. Any other advice, tommorow, I'm gonna change the fuel filter but, something tells me thats not gonna do any good. Any other advice? Rough idle is the symptoms and when I clear the code, the car warms up and throws a misfire code in cylinder number 4. Thats the second cylinder from the back on the passenger side, right? Any help would be appreciated.