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

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, compression tester, multimeter.
• Gather necessary parts for replacement (spark plug, ignition coil, or fuel injector as needed).
• Safety Warnings: Disconnect the battery before working on electrical systems. Allow the engine to cool before proceeding.

2. Replace Spark Plug

1. Remove the ignition coil from cylinder 1 by unscrewing the mounting bolts.
2. Disconnect the electrical connector to the ignition coil.
3. Remove the spark plug using a spark plug socket.
4. Inspect the old spark plug; replace it with a new one if it shows signs of wear (e.g., carbon fouling, gap deterioration).
5. Install the new spark plug and tighten it to the manufacturer's specified torque (typically 13-15 ft-lbs).
6. Reattach the ignition coil and connect the electrical connector.

3. Replace Ignition Coil (if necessary)

1. If the misfire persists after replacing the spark plug, remove the ignition coil from cylinder 1 as described above.
2. Install a new ignition coil, ensuring it is seated properly in the spark plug well.
3. Reconnect the electrical connector and secure it with the mounting bolts.

4. Replace Fuel Injector (if applicable)

1. If the problem continues, remove the fuel rail to access the fuel injector for cylinder 1.
2. Disconnect the fuel line and electrical connector from the injector.
3. Remove the fuel injector from the rail and replace it with a new one.
4. Reinstall the fuel rail, ensuring all connections are secure.