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

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool down before beginning work.

2. Replace Spark Plug

• Sub-steps:
  1. Remove the engine cover if equipped (use a socket set).
  2. Unplug the ignition coil connector and remove the ignition coil (use the socket set).
  3. Use a spark plug socket to remove the spark plug from cylinder 1.
  4. Inspect the old spark plug; if worn, replace it with a new spark plug (specify brand and gap as per manufacturer’s specification).
  5. Torque the new spark plug to the manufacturer’s specification (typically around 13-16 lb-ft).
  6. Reinstall the ignition coil and reconnect the electrical connector.

3. Replace Ignition Coil (if applicable)

• Sub-steps:
  1. If the ignition coil was confirmed faulty, remove it from the cylinder head (already completed in step 2).
  2. Install the new ignition coil and ensure it clicks into place.
  3. Reconnect the ignition coil connector.

4. Inspect/Replace Fuel Injector (if applicable)

• Sub-steps:
  1. Disconnect the fuel injector connector for cylinder 1.
  2. Remove the fuel rail (ensure fuel pressure is relieved first).
  3. Replace the fuel injector if it is found defective. Ensure it is properly seated and connected.
  4. Reinstall the fuel rail and reconnect all connectors.