1999 Dodge Avenger check engine light

I have a 99 Dodge Avenger V6. The check engine light keeps coming on. Sometimes it's blinking, sometimes it's steady. We've checked the code w/ handheld computer & it reads P0302. Cylinder #2 misfire detected. I've replaced disributor cap, rotor, wires, plugs & gasket for upper manifold. We turned off the check engine light & everything was good for about 2 weeks. Now, it's on again reading the same code. The spark plug looks okay, no signs of misfire. Do you have any advice?
Thank you.