how to fix the P0300 code on my Toyota Corolla E170 (2013-2019)

Solution

1. Preparation

• Tools Required: OBD-II scanner, spark plug socket, multimeter, compression tester, fuel injector cleaning kit.
• Disconnect the negative battery terminal to ensure safety.

2. Spark Plug Inspection and Replacement

• Remove the engine cover (if applicable) using a socket set.
• Use a spark plug socket to remove each spark plug, inspecting them for wear, cracks, or carbon buildup.
• If any spark plugs are damaged or worn, replace them with OEM or equivalent parts.
• Torque the new spark plugs to the manufacturer’s specified value (typically 13-15 lb-ft).

3. Ignition Coil Inspection

• Remove the ignition coils by unscrewing the bolts securing them to the valve cover.
• Use a multimeter to test each ignition coil's resistance (check service manual for specific values).
• Replace any faulty ignition coils with new ones, ensuring they are seated properly.

4. Fuel Injector Inspection

• Disconnect the fuel injector connectors and remove the fuel rail (if necessary).
• Clean the fuel injectors using a fuel injector cleaning kit according to the manufacturer's instructions.
• Reinstall the fuel injectors and ensure all connectors are securely attached.

5. Vacuum Leak Inspection

• Visually inspect all vacuum hoses for cracks, splits, or loose connections.
• Use a smoke machine or carburetor cleaner to check for any leaks while the engine is running.
• Replace any damaged hoses or seals found during the inspection.

6. Compression Test

• Remove all spark plugs and insert the compression tester into the spark plug holes.
• Crank the engine for a few seconds and record the compression readings for each cylinder.
• If any cylinder shows significantly lower compression, further investigation is required to determine the cause.