[Noob question] Cylinders misfiring, should I replace spark plugs or coil packs?

[KNGBEAR]

A friend ran some software on my car and it showed 3 of the 4 cylinders misfiring (error codes P0299, P0303, P0304, P0302, P130A, and P0300). Should I replace the spark plugs, the coil packs, or both?

What brands/retailers should I look at buying from?

If I need spark plugs, what should I "size" them at? Sorry, I forget the proper term.



Copy-paste of the error codes:

6 Faults Found:
5671 - Boost Pressure Regulation
P0299 00 [096] - Control Range Not Reached
Intermittent - Not Confirmed - Tested Since Memory Clear

4060 - Cylinder 3
P0303 00 [100] - Misfire Detected
Intermittent - Not Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 1
Mileage: 143462 km
Date: 2016.10.06
Time: 18:37:48

Engine speed: 3759.00 /min
Normed load value: 87.5 %
Vehicle speed: 111 km/h
Coolant temperature: 95 °C
Intake air temperature: 17 °C
Ambient air pressure: 880 mbar
Voltage terminal 30: 13.216 V
Unlearning counter according OBD: 72

4063 - Cylinder 4
P0304 00 [100] - Misfire Detected
Intermittent - Not Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 1
Mileage: 143462 km
Date: 2016.10.06
Time: 18:37:48

Engine speed: 3759.00 /min
Normed load value: 87.5 %
Vehicle speed: 111 km/h
Coolant temperature: 95 °C
Intake air temperature: 17 °C
Ambient air pressure: 880 mbar
Voltage terminal 30: 13.216 V
Unlearning counter according OBD: 72

4057 - Cylinder 2
P0302 00 [236] - Misfire Detected
MIL ON - Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 1
Mileage: 143792 km
Date: 2016.10.07
Time: 20:16:19

Engine speed: 1864.50 /min
Normed load value: 33.7 %
Vehicle speed: 65 km/h
Coolant temperature: 96 °C
Intake air temperature: 20 °C
Ambient air pressure: 800 mbar
Voltage terminal 30: 13.169 V
Unlearning counter according OBD: 40

7960 - Cylinder Disabling
P130A 00 [032] - -
Intermittent - Not Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 1
Mileage: 143792 km
Date: 2016.10.07
Time: 20:16:34

Engine speed: 1972.50 /min
Normed load value: 17.6 %
Vehicle speed: 58 km/h
Coolant temperature: 96 °C
Intake air temperature: 21 °C
Ambient air pressure: 800 mbar
Voltage terminal 30: 13.358 V
Unlearning counter according OBD: 39

4051 - Random/Multiple Cylinder Misfire Detected
P0300 00 [236] - -
MIL ON - Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 2
Mileage: 143462 km
Date: 2016.10.06
Time: 18:37:48

Engine speed: 3759.00 /min
Normed load value: 87.5 %
Vehicle speed: 111 km/h
Coolant temperature: 95 °C
Intake air temperature: 17 °C
Ambient air pressure: 880 mbar
Voltage terminal 30: 13.216 V
Unlearning counter according OBD: 40

[charny]

If you are having multiple misfires it is most likely an issue with you vacuum/pcv system. If you can't visually find the leak or problem area you should have it smoke tested. Also mileage and maintenance history are also helpful when diagnosing a problem. There are plenty of threads on here regarding cool and plug selection and will also cover proper spark plug gapping for your application.