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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface, and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Replace Spark Plug

• Remove the ignition coil from cylinder 1 by unbolting it (if applicable) and disconnecting the electrical connector.
• Use a spark plug socket and ratchet to remove the old spark plug.
• Inspect the spark plug gap and replace it with a new spark plug that meets OEM specifications.
• Reinstall the ignition coil and reconnect the electrical connector.

3. Test or Replace Ignition Coil

• If the spark plug replacement does not resolve the issue, test the ignition coil using a multimeter for primary and secondary resistance.
• If the coil is defective, remove it from the engine and replace it with a new unit, ensuring proper seating and connection.

4. Clean or Replace Fuel Injector

• If the ignition coil is functional, remove the fuel injector for cylinder 1.
• Clean the injector using a fuel injector cleaning kit or replace it with a new injector if cleaning does not resolve the issue.
• Reinstall the injector, ensuring proper O-ring placement and connection.

5. Perform Compression Test

• If the misfire persists, perform a compression test on cylinder 1.
• If compression is low, inspect for potential issues such as valve problems, head gasket failure, or piston ring wear. Repair as necessary.