Codes PO300, PO301 and P0507, fuel injected locations?

With those codes it sounds like a vacuum leak. That cause a higher idle because the extra air makes the system add fuel to compensate. The misfire codes would show up for the same reason. Finding the leak will require a visual inspection first, look at the vacuum lines for damage or looseness. If they all look okay take a can of starter fluid or an unlit propane torch and start the engine and move the torch around or spray the fluid on the lines, around the intake manifold and listen for the engine to change. Look in the area that made it change. Then you repair the cause of the leak.

https://www.2carpros.com/articles/automotive-engine-vacuum-leak-symptoms
https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge