2003 civic lx 1.7L has a malfunction lamp on intermittently. When on there is a rough idle, but not always. When the light is off, there is no performance problem. The code is p0302, indicating cylinder2 is misfiring. 10 months ago, I had the valves redone by the dealer due to no start, no compression. Also replaced plugs, timing belt, water pump. Can this be a fuel or gas cap issue, or would that set an emissions code? Is it damaging to continue driving since the light is intermittent? Any help as to the cause will be appreciated.