how to fix P0300 code on my Toyota RAV4 Fourth Generation (2013-2018)

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, fuel pressure gauge, compression tester, multimeter.
• Safety Warnings: Disconnect the battery before working on electrical systems. Allow the engine to cool before opening any components.

2. Replace Spark Plugs

• Remove the engine cover (if applicable) using a socket set.
• Disconnect the ignition coils by unhooking the wiring harness.
• Remove the ignition coils using the socket set; set aside.
• Use a spark plug socket to remove the spark plugs; inspect and replace them with OEM specifications.
• Reinstall the ignition coils and reconnect the wiring harness.

3. Check and Replace Ignition Coils

• Test the ignition coils using a multimeter to check resistance; replace any faulty coils.
• If replacing, remove the defective ignition coils with a socket set.
• Install new ignition coils following the manufacturer's specifications and torque values.

4. Inspect and Clean Fuel Injectors

• Use a fuel pressure gauge to check the fuel pressure; compare it to OEM specifications.
• If pressure is low, remove the fuel injectors using a socket set.
• Clean the injectors using an ultrasonic cleaner or replace them if clogged.
• Reinstall the fuel injectors and ensure all connections are secure.

5. Address Vacuum Leaks

• Visually inspect all vacuum lines for cracks or disconnections.
• Replace any damaged vacuum lines.
• If necessary, use a smoke machine to detect any hidden leaks.

6. Perform Compression Test

• Remove the spark plugs for access.
• Insert the compression tester into the spark plug holes and crank the engine.
• Record the compression readings; if they are below specifications, further engine diagnosis may be required.