how to fix my Toyota Highlander’s engine misfire problem

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety.
• Allow the engine to cool before proceeding.

2. Replace Spark Plugs

• Remove the ignition coil harness by gently pulling it away from the coil.
• Remove the ignition coils using a socket set.
• Inspect and replace spark plugs using a spark plug socket. Ensure proper gap settings per manufacturer specifications.
• Reinstall the ignition coils and reconnect the harness.

3. Check and Replace Ignition Coils (if necessary)

• If the diagnostic steps indicated faulty ignition coils, remove the affected coils as described above.
• Install new ignition coils, ensuring they are seated properly and secure.

4. Inspect and Clean Fuel Injectors

• Remove the fuel rail assembly, taking care to disconnect any electrical connectors and fuel lines.
• Use a fuel injector cleaner or ultrasonic cleaner to clean the injectors.
• Reinstall the fuel rail and ensure all connections are tight.

5. Test and Repair Vacuum Leaks

• Visually inspect vacuum hoses and connections for cracks or disconnections.
• Replace any damaged hoses or seals.
• Use a smoke machine or carburetor cleaner to detect leaks if necessary.