A code P0301 may mean that one or more of the following has happened:
Faulty spark plug or wire
Faulty coil (pack)
Faulty oxygen sensor(s)
Faulty fuel injector
Burned exhaust valve
Faulty catalytic converter(s)
Running out of fuel
Poor compression
Defective computer
Read more at: OBD-II Trouble Code: P0301 Cylinder 1 One Misfire Detected
Faulty spark plug or wire
Faulty coil (pack)
Faulty oxygen sensor(s)
Faulty fuel injector
Burned exhaust valve
Faulty catalytic converter(s)
Running out of fuel
Poor compression
Defective computer
Read more at: OBD-II Trouble Code: P0301 Cylinder 1 One Misfire Detected
What cap? The oil cap? If so, you may want to do a compression test to see if you have a head gasket leak.There’s a cloudy white residue when you look under the cap.