how to fix P0300 code on my Toyota Corolla E210 (2019-2024)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety.
• Allow the engine to cool before performing any inspections.

2. Inspect and Replace Spark Plugs

1. Remove the ignition coil cover (if applicable) using a socket set.
2. Disconnect the electrical connector from each ignition coil.
3. Remove the ignition coils using a socket wrench.
4. Inspect the spark plugs for wear; replace them if they are worn, damaged, or have excessive carbon buildup.
5. Install new spark plugs, ensuring they are gapped correctly as per manufacturer specifications.
6. Reinstall the ignition coils and reconnect the electrical connectors.

3. Inspect and Test Ignition Coils

1. Use a multimeter to test the resistance of each ignition coil. Compare with specifications in the service manual.
2. If any ignition coil is out of specification, replace it with a new coil.
3. Reinstall the ignition coils after testing.

4. Inspect Fuel Injectors

1. Remove the fuel injector rail by loosening the bolts securing it in place.
2. Carefully detach the fuel injectors from the rail.
3. Inspect each injector for clogs or leaks. Clean or replace as necessary.
4. Reattach the injectors and fuel rail securely.

5. Check for Vacuum Leaks

1. Start the engine and listen for hissing sounds around the intake manifold and vacuum lines.
2. Use a smoke tester or carburetor cleaner to identify any vacuum leaks.
3. Repair or replace any damaged vacuum hoses or gaskets.

6. Verify Fuel Pressure

1. Attach a fuel pressure gauge to the fuel rail Schrader valve.
2. Turn the ignition key to the "ON" position (do not start the engine) and check the pressure.
3. Compare the reading to the specifications in the service manual. If low, inspect the fuel pump and filter.