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

Solution

1. Preparation

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

2. Replace Spark Plug

• Sub-steps:
  1. Remove the engine cover if applicable.
  2. Disconnect the ignition coil connector for cylinder 1.
  3. Remove the ignition coil by unscrewing the retaining bolt and pulling it out carefully.
  4. Unscrew the old spark plug using a spark plug socket and ratchet.
  5. Install the new spark plug, ensuring it is gapped correctly to manufacturer specifications (typically around 0.044 inches for a Corolla).
  6. Torque the spark plug to the manufacturer's recommended specification (usually around 13 lb-ft).
  7. Reinstall the ignition coil and reconnect the connector.

3. Replace Ignition Coil (if necessary)

• Sub-steps:
  1. If the ignition coil was found faulty during diagnostics, procure a new ignition coil compatible with the 2019-2024 Corolla.
  2. Remove the old ignition coil as described in the previous step.
  3. Install the new ignition coil in place, ensuring it is seated properly.
  4. Reconnect the ignition coil connector and secure it with the retaining bolt.

4. Clean or Replace Fuel Injector (if necessary)

• Sub-steps:
  1. If the fuel injector is clogged, remove it from the fuel rail.
  2. Clean the injector using a professional-grade injector cleaning kit or replace it with a new one if severely damaged.
  3. Reinstall the cleaned or new fuel injector, ensuring it is sealed properly.

5. Reassemble and Reconnect Battery

• Sub-steps:
  1. Reinstall any components removed during the procedure (engine cover, etc.).
  2. Reconnect the negative battery terminal.
  3. Start the engine and let it idle for a few minutes to check for any abnormal sounds or issues.