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

Solution

1. Preparation

• Gather tools and parts needed.
• Disconnect the negative battery terminal to prevent electrical shock.
• Allow the engine to cool down before starting work.

2. Inspect and Replace Spark Plug

• Tools Required: Spark plug socket, ratchet, torque wrench.
• Remove the ignition coil from cylinder 1:
  • Unscrew the mounting bolts and disconnect the electrical connector.
• Remove the spark plug:
  • Use the spark plug socket to unscrew and remove the old spark plug.
• Inspect the spark plug:
  • Check for signs of wear or fouling. Replace if necessary.
• Install the new spark plug:
  • Thread the spark plug into the cylinder head and tighten to the manufacturer's torque specification (typically around 13-16 lb-ft).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Check and Replace Ignition Coil

• If the spark plug is in good condition, test the ignition coil:
  • Use a multimeter to check for primary and secondary resistance.
• If the ignition coil is faulty, replace it:
  • Remove the old ignition coil and install a new one.
  • Ensure proper seating and reconnect the electrical connector.

4. Inspect Fuel Injector

• Test the fuel injector for cylinder 1:
  • Use a noid light or multimeter to check for electrical signal.
• If the injector is faulty, replace it:
  • Disconnect the fuel line and electrical connector.
  • Remove the old injector and install the new one, ensuring proper seating and connection.

5. Perform Compression Test (if needed)

• If misfire persists, perform a compression test on cylinder 1:
  • Remove spark plug from cylinder 1.
  • Insert compression tester and crank the engine.
  • Compare compression readings to factory specifications. If low, further diagnosis may be needed.