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

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, fuel pressure gauge, multimeter, compression tester.
• Ensure the vehicle is parked on a flat surface and the engine is cool. Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Ignition Components

• Sub-steps:
  1. Remove the engine cover (if applicable) using a socket set.
  2. Disconnect the ignition coils from the electrical connectors.
  3. Remove the ignition coils using a socket wrench.
  4. Inspect the spark plugs for wear or fouling; replace if necessary.
  5. Install new ignition coils and reconnect the electrical connectors.
  6. Reattach the engine cover.

3. Check Fuel System

• Sub-steps:
  1. Connect a fuel pressure gauge to the fuel rail Schrader valve.
  2. Turn the ignition to the ON position (do not start the engine) to check for fuel pressure.
  3. Refer to the specifications; replace the fuel pump or filter if the pressure is below the manufacturer's specifications.
  4. Reconnect the fuel pressure gauge and ensure there are no leaks.

4. Inspect Vacuum Lines and Air Intake

• Sub-steps:
  1. Visually inspect all vacuum lines for cracks or disconnections and replace as necessary.
  2. Check the MAF sensor for dirt or debris; clean it with MAF sensor cleaner.
  3. Ensure the air filter is clean and free of obstructions; replace if needed.

5. Perform Compression Test

• Sub-steps:
  1. Remove spark plugs using a socket wrench.
  2. Insert the compression tester into the spark plug hole of each cylinder one at a time.
  3. Crank the engine and record the compression readings; compare against manufacturer specifications.
  4. Address any cylinders with low compression by inspecting for valve or piston issues.