Have the diagnostic codes always been consistent and the same? That is after replacing all the mentioned parts, cylinder 1 and cylinder 3 still have misfire? If yes, I would swap injector #1 into #4 position and move #4 injector to cylinder #1. Clear all diagnostic codes. Run engine. If misfire now appears on cylinder #4 and #1 cylinder has no misfire, then the problem is attributable to a fuel injector issue.