The meaning of car engine error code P0300 is that the engine is detecting multi-cylinder misfires. This is caused by engine spark plug leak, ceramic leak, electrode ablation and other conditions. Specifically, the operation steps are as follows:
1. Remove the high voltage wire from the cylinder head upwards.
2. Use a special spark plug tool to loosen the spark plug.
3. Use the high tension wire to remove the spark plug.
4. Install the new spark plug onto the engine.
5. Reinsert the vehicle's high voltage wire into the spark plug.