how to fix a P0301 code in my Toyota Corolla E170 (2013-2019)

Solution

1. Preparation

• Tools Required: OBD-II scanner, spark plug socket, multimeter, compression tester, noid light, basic hand tools
• Disconnect the negative battery terminal to prevent any electrical shorts.

2. Replace Spark Plug

• Remove the ignition coil from cylinder 1:
  • Disconnect the electrical connector.
  • Remove the retaining bolt with a socket.
  • Gently pull the coil out.
• Remove the spark plug:
  • Use a spark plug socket to unscrew and remove the old spark plug.
• Install the new spark plug:
  • Apply anti-seize lubricant on the threads (if required).
  • Torque the spark plug to the manufacturer's specification (typically around 13-16 lb-ft).
• Reinstall the ignition coil:
  • Place the coil back onto the spark plug and secure with the bolt.
  • Reconnect the electrical connector.

3. Test Ignition Coil

• If the coil was found faulty during diagnostics:
  • Replace the ignition coil with a new one.
  • Ensure it is securely seated and connected.

4. Inspect and Clean Fuel Injector

• If the injector was suspected of malfunctioning:
  • Remove the fuel injector from cylinder 1.
  • Clean the injector using an appropriate fuel injector cleaner or ultrasonic cleaner.
  • Reinstall the injector and ensure all connections are secure.

5. Check Compression

• If the compression test indicated low pressure:
  • Inspect for potential head gasket failure, valve issues, or piston damage.
  • Repair as necessary, which may involve more extensive engine work.