how to deal with the P0301 code in my Toyota Highlander XU70 (2020-Present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative terminal of the battery to prevent electrical shock.
• Ensure the engine is cool before starting any work.

2. Inspect and Replace Spark Plug

• Tools Required: Socket set, torque wrench, spark plug socket.
• Remove the engine cover, if necessary, to access cylinder 1.
• Disconnect the ignition coil connector and remove the coil from cylinder 1.
• Remove the spark plug using the spark plug socket, and inspect it for wear or fouling.
• If needed, replace the spark plug with a new one, ensuring it is gapped according to manufacturer specifications (usually around 0.044 inches for Toyota).
• Reinstall the ignition coil and reconnect the connector.

3. Check and Replace Ignition Coil (if necessary)

• Tools Required: Socket set.
• If the ignition coil is damaged or the spark plug replacement does not resolve the issue, remove the ignition coil from cylinder 1.
• Replace it with a new ignition coil that is compatible with the vehicle.
• Reinstall the ignition coil and ensure it is securely connected.

4. Inspect Fuel Injector

• Tools Required: Fuel injector removal tool (if necessary), multimeter (for testing).
• If the spark plug and ignition coil are functioning correctly, check the fuel injector on cylinder 1.
• Disconnect the fuel injector connector and test the resistance using a multimeter. Compare the readings with the manufacturer’s specifications.
• If the fuel injector is faulty, replace it with a new one.

5. Recheck and Clear Codes

• Reconnect the battery terminal.
• Start the engine and allow it to reach operating temperature.
• Use an OBD-II scanner to clear the P0301 code.
• Monitor the engine for any reoccurrence of the code.