how to fix P0301 code in 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 down if it has been running.

2. Replace Spark Plug

• Tools Required: Socket set, ratchet, torque wrench.
• Remove the ignition coil from cylinder 1 by unscrewing the mounting bolts.
• Disconnect the electrical connector from the ignition coil.
• Remove the spark plug using a spark plug socket.
• Inspect the old spark plug for wear; replace it with a new spark plug, ensuring it is gapped correctly per manufacturer specifications (typically around 0.043 inches for a Corolla).
• Reinstall the ignition coil and secure it with bolts; reconnect the electrical connector.
• Torque the ignition coil bolts to the manufacturer's specified value (usually about 8 ft-lbs).

3. Replace Ignition Coil (if necessary)

• If the ignition coil was found faulty during inspection, replace it.
• Remove the old ignition coil as described above.
• Install the new ignition coil and ensure it is seated properly.
• Reconnect the electrical connector and secure with bolts.

4. Check Fuel Injector

• Tools Required: Fuel pressure gauge.
• Disconnect the fuel line from the fuel rail (use caution with fuel spray).
• Remove the fuel injector for cylinder 1 by unscrewing it from the rail.
• Inspect the injector for clogs or damage; clean or replace if necessary.
• Reinstall the fuel injector and reconnect the fuel line, ensuring there are no leaks.

5. Perform Compression Test

• Remove the spark plug from cylinder 1.
• Attach the compression gauge to the spark plug hole.
• Crank the engine to obtain a compression reading; compare to the manufacturer’s specifications (usually 180-210 psi).
• If compression is low, further investigation is required for possible valve or piston issues.