misfire

Hey all! Got a Protege5 with an intermittent misfire; gives codes p0300 and p0660. Replaced the plugs and wires (except the coils) and cleaned the EGR valve, no change. Sometimes she fires up fine and will drive a few miles, mostly she just misfires or idles very roughly. I'm kind of low budget...

I have a problem with random misfires that i cant figure out. I have recently replaced the spark plugs and wires. i somehow think its related to my intake. I had a friend (without my permission) cut the plastic connecting piece that went near the radiator off, leaving a gaping hole on the intake...

After My install of a 626 intake manifold along with the mp3 ecu I have been experiencing a misfire for the past month. At first I thought is was due to a faulty spark plug which i replaced and the problem seemed to go away but now came back. I then replaced the wires and a week later the...