You’d also want to know that misfire codes do not tell you about spark. Your spark might be perfectly fine.
The misfire code just means that combustion didn’t take place. Spark is only one thing you need for combustion. You also need compression. So pull the plugs back out and check the compression. You also need the correct fuel/air mix. So you’ll want to check out the #4 fuel injector. You can inspect the wiring & harness. You can use a “noid” light to have a look at the power supply to the injector. You can use an ohmeter to check the injectors resistance. You can also swap the #4 injector with another and find out if the misfire moves with the injector.