how to fix P0300 code for random misfires on Toyota RAV4 XA50 (2019-2024)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Ensure the engine is cool before working on the ignition system.

2. Replace Spark Plugs

• Tools Required: Spark plug socket, torque wrench, ratchet, dielectric grease.
• Remove the ignition coil covers if applicable.
• Use a spark plug socket to remove old spark plugs and inspect for signs of wear or damage.
• Apply dielectric grease to the new spark plug threads to prevent seizing.
• Install new spark plugs to the manufacturer’s specified torque (typically 13-15 lb-ft for most Toyota engines).

3. Inspect and Replace Ignition Coils

• Tools Required: Ratchet and socket set, multimeter (if testing).
• Remove the ignition coils from the spark plug wells.
• Check the resistance of each ignition coil using a multimeter; refer to the service manual for specifications.
• Replace any faulty ignition coils with new ones, ensuring they are seated correctly.

4. Clean or Replace Fuel Injectors

• Tools Required: Fuel injector cleaning kit or new injectors, safety glasses, gloves.
• If cleaning, disconnect the fuel lines and connect the cleaning kit according to the manufacturer’s instructions.
• If replacing, remove the old fuel injectors and install new ones, ensuring O-rings are lubricated with engine oil for a proper seal.

5. Check for Vacuum Leaks

• Tools Required: Smoke machine or propane torch (for testing), wrench set.
• Use a smoke machine to introduce smoke into the intake system and identify leaks.
• Repair any vacuum leaks found by replacing cracked hoses or gaskets.