2013 Honda Fit Sport 130k miles.
Car looses power when accelerating and it sounds like its misfiring while idling. The original error code on my OBD2 scanner said cylinder 4 misfire. I didn't write down the number.

So far, I've replaced 4 spark plugs, 2 iginition coils, 4 fuel injectors and the entire fuel pump assembly and the problem hasn't been resolved.

Any suggestions?

 

So after all the parts replacement you are still getting a P0304, cylinder 4 misfire? With that number of miles have you ever done a valve adjustment? Valve adjustment issues can cause misfire codes. You might want to go there next.