P0300 is a random misfire code, possibly caused by whatever is causing the P2A00. Possible causes of P2A00:
- Air Fuel Ratio (A/F) Sensor Bank 1 Sensor 1
- Air Fuel Ratio (A/F) Sensor Bank 1 Sensor 1 harness is open or shorted
- Air Fuel Ratio (A/F) Sensor Bank 1 Sensor 1 circuit poor electrical connection
- Fuel pressure
- Fuel injector
- Intake air leaks
Read more:
P2a00 Nissan Air Fuel Ratio Sensor Circuit Range/Performance Bank 1 Sensor 1 OBDII Engine Light Trouble Code | Engine-Codes.com