how to fix P0300 misfire in Toyota Corolla E170 (2013-2019)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• 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

• Remove the ignition coil cover (if applicable) using a socket set.
• Disconnect the ignition coil connector and remove the ignition coil using a socket wrench.
• Remove the spark plug using a spark plug socket and ratchet.
• Inspect the spark plug for wear, deposits, or damage; replace if necessary.
• Install new spark plug at the manufacturer’s specified torque (typically around 13-15 lb-ft).
• Reinstall the ignition coil and connector.

3. Check and Replace Ignition Coils

• If the spark plugs are fine, inspect ignition coils for signs of damage.
• Replace any faulty ignition coils with new components.
• Ensure correct installation and connect the wiring harness securely.

4. Fuel Injector Cleaning/Replacement

• If misfire persists, check fuel injectors.
• Remove injectors from the fuel rail with a fuel injector removal tool.
• Clean the injectors using a professional cleaning kit or replace them if clogged or faulty.
• Reinstall injectors and connect the fuel rail.

5. Inspect Air Intake and Vacuum Hoses

• Check the intake manifold for leaks and ensure all hoses are securely connected.
• Replace any damaged hoses and clean the throttle body as needed.