[SF-Rockster]

So the story is that my car has been getting misfire codes for cylinder 4 and now also cylinder 2.
I swapped plugs around no change.
Spark plugs swapped around still no change.
This happens when I don't drive the car for a few days.
After warming up the engine it drives fine.
Checked compressions and it's 150psi.
Is the compression okay?
Fuel delivery problem?
I also have an aftermarket amp (Phoenix Gold 5 channels)that powers the speakers and sub.
Also have a CAP hooked up as well.
Would a low battery cause this too?
CEL flashes and stays solid. Check codes and it shows misfire cylinder 2 and 4 and random misfire.

Hope you guys can help.

Thanks in advance