Car's ECU detects disbalance of the engine working cycle parameters, usually variations of crankshaft revolving speed, that caused by random/multiple misfires in engine cylinders. P0300 indicates generic error with undefined cylinder. P030x (where x=1,2,3,...) points exact number of cylinder with detected misfires.
- Check Engine dashboard light is ON
- Unstable work and sound from engine: stumbles, shakes
- Possible lack of power and car dynamic, engine shakes when accelerating
- Could be issues with engine start
- Faulty or worn-our spark plugs or connectors
- Faulty coil
- Faulty fuel injector
- Low fuel pressure
- Exhaust system issues
- Low quality of the fuel
Severity - Major
Need to be fixed ASAP. With a time could lead other systems malfunctioning and increasing of repair casts.
- Be sure using a quality fuel. If not, change fuel, clear code and wait few days driving if it re-appears.
- Check spark plugs and coil connectors and wires, replace, if required
- Visually inspect spark plugs, replace, if required
- Review and correct, if required, fuel injectors, distributor cap, compression, other systems that have DTCs.