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 prevent electrical shock.
• Allow the engine to cool down before starting work.

2. Replace Spark Plug

• Tools Required: Spark plug socket, ratchet, torque wrench
• Remove the ignition coil on cylinder 1 by unscrewing the retaining bolts and gently pulling it out.
• Use the spark plug socket to unscrew and remove the spark plug from cylinder 1.
• Inspect the old spark plug for signs of wear or damage. If necessary, replace with a new spark plug.
• Torque the new spark plug to the manufacturer-recommended specification (typically around 13-16 lb-ft).
• Reinstall the ignition coil, ensuring a snug fit.

3. Inspect and Replace Ignition Coil

• Tools Required: Ratchet, socket set
• If the ignition coil is found to be defective, remove it from cylinder 1.
• Insert the new ignition coil, ensuring it is properly seated.
• Tighten the retaining bolts to the specified torque (usually around 7-9 lb-ft).

4. Clean or Replace Fuel Injector

• Tools Required: Fuel injector cleaning kit or replacement injector
• If the fuel injector is suspected to be clogged, use a fuel injector cleaning kit to flush it.
• If cleaning does not resolve the issue, remove the fuel injector and replace it with a new one.
• Ensure O-rings are properly lubricated and seated to prevent leaks.

5. Reassemble and Conduct Final Checks

• Reconnect the negative battery terminal.
• Start the engine and allow it to idle to check for smooth operation.
• Ensure no check engine light is illuminated.