Codes P0204 and P0304, misfire on warm start only?

So, the code P0204 will cause the P0304 code. I would check the electrical connector at the #4 and if it looks okay replace the fuel injector.

P0204 - Injector Circuit/Open - Cylinder 4: This code indicates a problem with the fuel injector circuit for Cylinder 4.

P0304 - Cylinder 4 Misfire Detected: This code signals that the engine's computer (ECU) has detected a misfire in Cylinder 4.

Here is a generic guide to help you step by step with instructions in the diagrams below to show you how on your car:

https://www.2carpros.com/articles/how-to-replace-a-fuel-injector

You will need to remove the upper intake manifold to do the job. Check out the images (below). Please let us know if you need anything else to get the problem fixed.

Thanks so much for the reply, Ken. This all seems beyond my capability, so I’ll take it to a mechanic. At least I have an idea of what the issue is. I appreciate your help.

Yep, it's good to know what you are getting into with the repair so there are no surprises. Please get back to me with how it turns out.