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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal.
• Allow the engine to cool down before starting work.

2. Inspect and Replace Spark Plugs

• Tools Required: Socket set, spark plug socket, torque wrench
• Remove the ignition coils by unscrewing and carefully pulling them out.
• Use a socket to remove each spark plug.
• Inspect the spark plugs for wear or carbon buildup; replace them if necessary.
• Install new spark plugs, ensuring to torque them to the manufacturer’s specification (typically around 13-15 lb-ft).

3. Inspect and Replace Ignition Coils

• Tools Required: Socket set, torque wrench
• Inspect each ignition coil for cracks or damage.
• Replace any faulty ignition coils by unscrewing them from the mounting bracket and disconnecting the electrical connector.
• Install the new ignition coils, ensuring they are securely fastened and properly connected.

4. Check and Repair Vacuum Leaks

• Tools Required: Smoke machine or carb cleaner, hose clamps
• Use a smoke machine to introduce smoke into the intake system to identify leaks, or spray carb cleaner around hoses and connections while the engine is running to check for changes in idle.
• Replace any damaged hoses or connections.

5. Test and Replace Fuel Injectors (if necessary)

• Tools Required: Fuel pressure gauge, multimeter
• Connect a fuel pressure gauge to the fuel rail to check for adequate pressure.
• If pressure is low, check the fuel pump and relay.
• If fuel injectors are suspected to be faulty, remove and test each injector with a multimeter for resistance; replace as needed.