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

Solution

1. Preparation

• Gather tools and parts needed for repair.
• Disconnect the negative terminal of the battery to ensure safety while working on the ignition system.

2. Replace Spark Plugs

• Remove the ignition coil cover (if applicable) using a socket set.
• Disconnect the ignition coil connectors and remove the ignition coils.
• Extract the old spark plugs using a spark plug socket.
• Install new spark plugs, ensuring proper torque (typically around 13 lb-ft).
• Reinstall ignition coils and reconnect connectors.

3. Inspect and Replace Ignition Coils (if necessary)

• Remove any necessary components to access the ignition coils.
• Visually inspect each coil for cracks or damage.
• If any coils are faulty, replace them with new units, ensuring they are seated properly.

4. Check and Repair Fuel System

• Connect a fuel pressure gauge to the fuel rail.
• Turn the ignition to the ON position (without starting) and check fuel pressure against specifications (typically around 43-50 psi for the Corolla).
• If pressure is low, inspect the fuel pump and filter and replace as needed.

5. Inspect and Repair Vacuum Leaks

• Visually inspect all vacuum lines for cracks or disconnections.
• Perform a smoke test if necessary to locate any hidden leaks.
• Replace any damaged vacuum hoses.

6. Verify Engine Compression

• Remove spark plugs and connect a compression tester to each cylinder.
• Crank the engine and note the readings; they should be within manufacturer specifications (typically around 180 psi).
• If any cylinder has low compression, further investigation is needed (e.g., valve issues, head gasket).