How can I trace power supply for the following codes P 1304- 06 misfiring

What is your question?

I noticed that some rates where in my engine and it seems I not receiving any power from the driver side cylinders all three. The coils are okay. Car is using too much fuel and is only using three cylinders from the passanger's side. Also I have a random misfire from codes P 0300 and P 1399. How do I fix this? What electrical cables should I trace? Is there a code I can trace that supplies power to these three cylinders?