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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery cable to prevent electrical shorts.
• Ensure the engine is cool before starting work.

2. Replace the Spark Plug

• Remove the ignition coil from cylinder 1:
  • Disconnect the electrical connector.
  • Remove the mounting bolts using a socket set.
  • Gently pull out the ignition coil.
• Remove the spark plug:
  • Use a spark plug socket to loosen and remove the spark plug.
• Install the new spark plug:
  • Check the gap according to manufacturer specifications (usually around 0.043 inches).
  • Install the spark plug and tighten to the recommended torque (typically around 13 lb-ft).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Inspect and Replace the Ignition Coil (if necessary)

• If the ignition coil appears damaged:
  • Remove the faulty ignition coil as previously instructed.
  • Install the new ignition coil, ensuring it is properly seated.
  • Reconnect the electrical connector.

4. Check Fuel Injector (if necessary)

• If the spark plug and ignition coil are fine but the code persists:
  • Use a fuel injector cleaning kit to clean the injector for cylinder 1.
  • If cleaning does not resolve the issue, replace the injector.

5. Compression Test (if necessary)

• If misfire symptoms continue:
  • Remove the spark plug again.
  • Insert a compression tester into cylinder 1.
  • Crank the engine and record the compression reading (should be within manufacturer specs).
  • If low, investigate potential valve or piston issues.