[thstone]

P0300 - Engine misfire
P0304 - Cyl 4 misfire
P0305 - Cyl 5 misfire
P0306 - Cyl 6 misfire

P1316 Misfire, Cylinder 4, Emission Relevant
P1317 Misfire, Cylinder 5, Emission Relevant
P1318 Misfire, Cylinder 6, Emission Relevant
P1319 Misfire, Emission Relevant

P1117 Oxygen Sensor Heating 1 After Catalytic Converter - Below Lower Limit


I would start cheap and easy:

- Swap the forward O2 sensors (each to the other side) to see if the problem on Bank 2 (cyls 4,5,6 on drivers side) moves with the sensor to Bank 1. If so, then you have a bad forward O2 sensor.
- Replace the MAF
- Inspect for an air leak - focus especially at the hoses and intake components on Bank 2