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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal.
• Allow the engine to cool if it has been running.

2. Replace Spark Plugs

• Sub-steps:
  1. Remove the engine cover if applicable.
  2. Disconnect the ignition coil connectors.
  3. Unscrew the ignition coils and remove them.
  4. Remove the old spark plugs using a spark plug socket.
  5. Install new spark plugs (torque to manufacturer specifications, typically around 13 lb-ft).
  6. Reinstall ignition coils and reconnect connectors.

3. Inspect and Replace Ignition Coils (if necessary)

• Sub-steps:
  1. Visually inspect ignition coils for cracks or signs of overheating.
  2. Replace any faulty coils with new ones (torque bolts to manufacturer specifications).
  3. Reconnect all connectors properly.

4. Clean or Replace Fuel Injectors

• Sub-steps:
  1. If cleaning, use a fuel injector cleaning kit according to the manufacturer's instructions.
  2. If replacing, remove the fuel rail and replace the injectors one by one.
  3. Ensure new o-rings are lubricated and seated properly.

5. Check Fuel Pressure

• Sub-steps:
  1. Connect a fuel pressure gauge to the fuel rail.
  2. Turn the ignition to the "on" position (without starting) and check the pressure (should match manufacturer specifications).
  3. If pressure is low, check the fuel pump and filter for issues.

6. Inspect for Vacuum Leaks

• Sub-steps:
  1. With the engine running, use a smoke machine or carburetor cleaner to check for vacuum leaks.
  2. Repair or replace any damaged hoses or gaskets found during inspection.