how to fix P0301 code on Toyota Corolla E210 (2019-2024)

Solution

1. Preparation

• Gather Tools and Parts: Ensure you have the necessary tools and replacement parts ready.
• Safety Warning: Disconnect the battery to prevent electrical shock.

2. Replace Spark Plug

• Tools Required: Socket set, torque wrench, spark plug socket.
• Sub-steps:
  1. Remove the engine cover if applicable.
  2. Disconnect the ignition coil connector for cylinder 1.
  3. Remove the ignition coil using a socket.
  4. Remove the old spark plug with a spark plug socket.
  5. Install the new spark plug and tighten it to the manufacturer's specified torque (typically around 13-15 lb-ft).
  6. Reinstall the ignition coil and reconnect the connector.

3. Replace Ignition Coil (if necessary)

• Tools Required: Socket set.
• Sub-steps:
  1. If the ignition coil was found defective during diagnostics, remove it as previously outlined.
  2. Install the new ignition coil, ensuring it is seated correctly.
  3. Reconnect the ignition coil connector.

4. Test Fuel Injector (if necessary)

• Tools Required: Fuel injector tester.
• Sub-steps:
  1. Disconnect the fuel injector connector for cylinder 1.
  2. Connect the fuel injector tester and follow its instructions to check for proper operation.
  3. Replace the fuel injector if it fails the test.

5. Check for Vacuum Leaks

• Tools Required: Vacuum gauge, smoke machine (optional).
• Sub-steps:
  1. Inspect all vacuum hoses connected to the intake manifold.
  2. Use a vacuum gauge to check for proper readings; a significantly low reading indicates a leak.
  3. Repair or replace any damaged hoses.