how to fix the P0300 code in my Toyota Corolla E210 (2019-2024)?

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Spark Plugs

• Sub-step 1: Remove the engine cover (if applicable) using a socket set.
• Sub-step 2: Disconnect the ignition coils from the spark plugs.
• Sub-step 3: Remove the spark plugs using a spark plug socket.
• Sub-step 4: Inspect the old spark plugs for wear; replace them with OEM or quality aftermarket plugs, ensuring the gap is set to specifications (typically around 0.043 inches).
• Sub-step 5: Reinstall the ignition coils and reconnect them.

3. Check and Replace Ignition Coils

• Sub-step 1: If misfires persist, remove the ignition coils one by one.
• Sub-step 2: Inspect for cracks or damage; test with a multimeter according to specifications (should typically be 0.5 to 1.5 ohms for primary resistance).
• Sub-step 3: Replace any faulty ignition coils with new units.

4. Inspect and Clean Fuel Injectors

• Sub-step 1: Disconnect the fuel injector connectors and remove them from the engine.
• Sub-step 2: Use a fuel injector cleaning kit or ultrasonic cleaner to clean the injectors.
• Sub-step 3: Reinstall the cleaned or new injectors and reconnect the connectors.

5. Check for Vacuum Leaks

• Sub-step 1: With the engine running, spray a carburetor cleaner around intake hoses and connections.
• Sub-step 2: Listen for changes in engine RPM, indicating a leak; replace any damaged hoses.

6. Test Fuel Pressure

• Sub-step 1: Attach a fuel pressure gauge to the fuel rail.
• Sub-step 2: Start the engine and check that the pressure meets manufacturer specifications (typically around 30-40 psi).
• Sub-step 3: If pressure is low, inspect the fuel pump and filter for issues.