I have the same issue, it's been parked since March, it started when changed the spark plugs with Denso iridium, throwing codes p0303 and p0304, returned back to old spark plugs, recheck the gap, changed the spark plugs, new set of wires, change the ignition coil, clean the fuel injectors, check the pressure in fuel lines, change the throttle body, change the rear O2 sensor, finally I changed the MAF, forgot to mention that I changed the fuel filter too, we thought the cause was the fuel as the car was idling fine with fuel aditive till reached the point of nothing help...with all of that still have misfire on cylender 3 and 4, both didnt move...still didnt get the time to do a compression test...probably this week...I am thinking in draining the fuel tank and add a new fuel? if didnt help will take it to dealer...