how to fix P0300 code in Toyota RAV4 Fifth Generation (2019-present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface.
• Disconnect the battery to prevent electrical accidents.

2. Inspect and Replace Spark Plugs

• Remove the engine cover if applicable.
• Using a socket wrench, remove the spark plug wire or ignition coil.
• Use a spark plug socket to carefully remove the spark plug.
• Inspect the spark plug for wear (fouling, cracks, or excessive gap).
• Replace with new spark plugs that meet OEM specifications (e.g., NGK or Denso).
• Reinstall the spark plug and reconnect the ignition coil or spark plug wire.

3. Test and Replace Ignition Coils

• With the engine off, disconnect the electrical connector from the ignition coil.
• Remove the ignition coil from the spark plug using a socket wrench.
• Use an ohmmeter to test the resistance of the ignition coil according to manufacturer specifications.
• If the coil is defective, replace it with a new one.
• Repeat for all ignition coils if necessary, then reconnect the electrical connectors.

4. Inspect and Clean Fuel Injectors

• Locate the fuel rail and remove the fuel injector electrical connectors.
• Detach the fuel rail from the engine to access the injectors.
• Use a fuel injector cleaning kit to clean each injector or replace any that show signs of clogging or failure.
• Reassemble the fuel rail and reconnect all connectors.

5. Check for Vacuum Leaks

• Visually inspect all vacuum lines connected to the intake manifold for cracks or disconnections.
• Use a smoke machine or carb cleaner spray around the intake area while the engine is running to check for leaks.
• Replace any damaged vacuum lines and ensure all connections are secure.