Mitsubishi Forum - Mitsubishi Enthusiast Forums - P0300 Please Help. Running out of ideas

Hi, I have a 2000 Mitsubishi Mirage DE, 1.8. 116,500 miles on it. (mostly freeway miles). I keep getting this random misfire code. I changed the spark plugs, wires, the 2 coils, PCV valve and used 1 can of Seafoam in a full gas tank. Still getting this code. I do notice when driving X amount of miles which is a random number, the the engine will vibrate a little bit and the light will come back on. same code. I reset the code and after a while it comes back on. Same way. vibrates a little and light back on. When I feel it vibrate a little and light turns on, I let off the gas and it smooths out back to normal. Does this sound fuel related? My next move is to change the fuel filter.