how to fix the P0301 code on my Toyota Corolla E170 (2013-2019)?

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, multimeter, compression tester, basic hand tools.
• Disconnect the negative battery terminal to ensure safety while working on the engine.

2. Replace Spark Plug and Ignition Coil

• Sub-steps:
  1. Remove the engine cover (if applicable) by unscrewing the bolts.
  2. Unscrew the ignition coil securing bolts and gently pull out the ignition coil from cylinder 1.
  3. Remove the spark plug using a spark plug socket and ratchet.
  4. Inspect the old spark plug for wear (carbon build-up, damage) and replace it with a new one (specification: NGK or Denso as per OEM).
  5. Install the new spark plug and tighten it to the manufacturer’s specified torque (typically around 13 lb-ft).
  6. Reinstall the ignition coil and secure it with the bolts.

3. Check and Replace Fuel Injector (if necessary)

• Sub-steps:
  1. Disconnect the electrical connector from the fuel injector on cylinder 1.
  2. Use a multimeter to test the injector's resistance (specification: typically around 12-16 ohms).
  3. If the injector is faulty, remove the fuel rail by unscrewing the mounting bolts and gently lifting it off.
  4. Remove the old injector from the fuel rail and replace it with a new OEM injector.
  5. Reinstall the fuel rail, ensuring all seals and O-rings are properly seated.

4. Inspect for Vacuum Leaks

• Sub-steps:
  1. Visually inspect the intake manifold gaskets and vacuum hoses for any visible cracks or disconnections.
  2. Use a smoke machine or carburetor cleaner to check for vacuum leaks while the engine is running.
  3. Repair or replace any damaged hoses or gaskets found during the inspection.

5. Reassemble and Reconnect

• Reinstall any components removed during the repair process (engine cover, electrical connectors).
• Reconnect the negative battery terminal.