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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety.
• Allow the engine to cool down before working.

2. Replace Spark Plug

• Tools Required: Socket set, torque wrench, ratchet.
• Remove the ignition coil cover if applicable.
• Disconnect the ignition coil connector and remove the ignition coil.
• Unscrew the spark plug using a spark plug socket.
• Replace with a new spark plug; torque to specifications (usually around 13 lb-ft or 17.6 Nm).
• Reinstall the ignition coil and reconnect the connector.

3. Inspect and Replace Ignition Coil

• If the spark plug was fine, test the ignition coil for cylinder 1 using a multimeter.
• If out of specification, replace the ignition coil with a new one.
• Reinstall the ignition coil and reconnect the connector.

4. Clean or Replace Fuel Injector

• If the issue persists, check the fuel injector for cylinder 1.
• Use a fuel injector cleaner to attempt to clear any clogs.
• If cleaning does not resolve the issue, replace the fuel injector with a new one.

5. Conduct Compression Test

• If misfire continues, perform a compression test on cylinder 1.
• If compression is low, internal engine repairs may be needed.