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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool if it has been running.

2. Replace Spark Plug

• Tools Required: Socket set, torque wrench, spark plug socket.
• Remove the ignition coil on cylinder 1 by unscrewing the mounting bolt and disconnecting the electrical connector.
• Remove the spark plug using a spark plug socket. Inspect it for wear or damage.
• Install the new spark plug by hand, then torque it to the manufacturer's specifications (typically around 13-16 lb-ft).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Replace Ignition Coil (If Necessary)

• Tools Required: Socket set, torque wrench.
• If the ignition coil was found faulty during inspection, remove the faulty coil as described above.
• Install the new ignition coil, ensuring it is seated properly.
• Torque the mounting bolt to the specified value (usually around 8-10 lb-ft).

4. Clean or Replace Fuel Injector (If Necessary)

• Tools Required: Fuel injector cleaner kit or replacement injectors.
• Disconnect the fuel line and electrical connector from the injector.
• Remove the injector from the rail, taking care to note any O-rings that need replacement.
• Clean the injector with a dedicated fuel injector cleaner or replace it with a new one.
• Reinstall the injector and reconnect all lines and connectors.

5. Check Engine Compression (If Necessary)

• Tools Required: Compression tester.
• Remove the spark plug from cylinder 1.
• Insert the compression tester into the spark plug hole and crank the engine.
• Record the compression reading. It should be within the manufacturer's specifications (usually around 180-200 psi).
• If compression is low, further investigation into the cylinder head or piston rings may be necessary.