how to resolve P0301 misfire code in 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. Inspect and Replace Spark Plug

• Tools Required: Socket set, torque wrench, gap gauge.
• Remove the ignition coil cover (if applicable).
• Disconnect the electrical connector from the ignition coil and remove the coil.
• Unscrew and remove the spark plug from cylinder 1 using a spark plug socket.
• Inspect the spark plug for wear or fouling; replace if necessary.
• Gap the new spark plug to the manufacturer specification (typically around 0.044 inches for the Corolla).
• Install the new spark plug and torque to the manufacturer's specifications (usually around 13 lb-ft).

3. Inspect and Replace Ignition Coil

• If the spark plug was not the issue, inspect the ignition coil for damage.
• Replace the ignition coil for cylinder 1 if it shows signs of wear or malfunction.
• Reinstall the ignition coil and reconnect the electrical connector, ensuring a secure fit.

4. Check Fuel Injector

• Tools Required: Fuel injector cleaner or replacement injector.
• Remove the fuel rail (if necessary) to access the injector for cylinder 1.
• Inspect the fuel injector for clogs or leaks. Clean or replace as needed.
• Reinstall the fuel rail and ensure all connections are secure.

5. Perform a Compression Test

• Tools Required: Compression gauge.
• Remove all spark plugs to allow for even cranking.
• Insert the compression gauge into the spark plug hole of cylinder 1.
• Crank the engine several times and record the compression reading.
• Compare the reading to the manufacturer's specifications (usually around 180 psi for a healthy engine). If low, further investigation may be needed.