how to fix P0300 misfire in Toyota RAV4 XA40 (2013-2018)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery to prevent electrical shorts during repairs.
• Safety glasses and gloves should be worn throughout the process.

2. Inspect and Replace Spark Plugs

• Remove the engine cover if applicable.
• Use a socket set to remove the spark plugs.
• Inspect the old spark plugs for wear; replace with OEM or quality aftermarket spark plugs if necessary (Torque to manufacturer specifications, usually around 13 ft-lbs).
• Reinstall spark plugs and reconnect any engine covers.

3. Check and Replace Ignition Coils

• Disconnect the electrical connector from each ignition coil.
• Remove the ignition coils using a socket set.
• Test each ignition coil with a multimeter (primary resistance should be 0.4-2.0 ohms; secondary resistance should be 6,000-15,000 ohms).
• Replace any faulty ignition coils with OEM parts (Torque to manufacturer's specifications).

4. Inspect Fuel Injectors

• Disconnect the fuel rail and electrical connectors from the injectors.
• Remove the fuel injectors using a fuel injector puller if necessary.
• Inspect injectors for clogs; clean or replace as needed.
• Reinstall the fuel injectors, ensuring proper seating and connection.

5. Check Vacuum Lines and Intake Manifold

• Visually inspect all vacuum lines for cracks or disconnections.
• Replace any damaged vacuum lines.
• If applicable, remove the intake manifold to inspect for leaks and replace gaskets if necessary.

6. Compression Test (if required)

• Remove spark plugs to allow for a compression test.
• Use a compression tester, cranking the engine as per tool instructions.
• Record readings; if any cylinder is below 100 psi, further investigation is warranted.