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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the battery to ensure safety.
• Allow the engine to cool completely before starting any repairs.

2. Replace Spark Plugs

• Remove the engine cover if applicable.
• Use a socket wrench to remove the spark plug boots and unscrew the spark plugs.
• Inspect the old spark plugs for excessive wear or deposits.
• Install new spark plugs, ensuring they are gapped correctly per manufacturer's specifications (typically around 0.044 inches).
• Torque the new spark plugs to the manufacturer’s specifications (usually 13 ft-lbs).

3. Inspect and Replace Ignition Coils

• Remove the bolts securing the ignition coils.
• Carefully pull the ignition coils out of their respective cylinders.
• Test each coil with a multimeter to ensure they are within resistance specifications (typically 0.5 to 1.5 ohms).
• Replace any faulty coils with new ones and ensure they are seated properly.

4. Check and Repair Fuel System

• Connect a fuel pressure gauge to the fuel rail.
• Turn the ignition to the "ON" position (do not start the engine) and check the fuel pressure; it should be within the manufacturer's specified range (usually 50-60 psi).
• If pressure is low, inspect the fuel filter, fuel pump, and fuel injectors for proper operation and replace if necessary.

5. Inspect for Vacuum Leaks

• Inspect all vacuum lines for cracks or disconnections.
• Use a smoke machine or carburetor cleaner to check for leaks around the intake manifold and throttle body.
• Repair any identified leaks by replacing faulty hoses or re-sealing connections.