Problems to repair Ford Focus 2008

Hi, I'm new here, I'm a mechanic, I have problems detecting the fault.
The car is a Ford Focus 2008, Zetec Rocam 1.6 engine, the fault makes it in fourth when you stretch it a lot, but more in fifth when you reach 110km. What the scanner throws is P300 and P304. I changed coils, spark plug wires, gasoline pump, replacement fuel, I made cylinder and rings cover due to low compression doubts. The escape also probes it. That waiting for your answers, thank you very much, a month ago that I rename with the car, even consult with mechanics in the area and nothing ...

Good morning, the failures in high generally of this vehicle are the gasoline filters both that brings the pump internally in the tank and the one that is at the exit of the tank, change them and you will see the improvements. I have one 2006 and presented the same fault as yours.