how to fix the check engine light code P0301 on Toyota Camry XV40 (2007-2011)

Solution

1. Preparation

• Gather tools and parts.
• Ensure the vehicle is parked on a flat surface, and the engine is cool.
• Disconnect the battery negative terminal to prevent electrical shorts.

2. Inspect and Replace Spark Plug

• Tools Required: Socket set, torque wrench, spark plug socket
• Remove the ignition coil from cylinder 1:
  • Disconnect the electrical connector.
  • Remove the mounting bolts and carefully pull the coil out.
• Remove the spark plug using the spark plug socket.
• Inspect the spark plug for wear, carbon build-up, or damage.
• Install a new spark plug, ensuring it is gapped according to manufacturer specifications (typically around 0.043 inches for Toyota).
• Torque the spark plug to the manufacturer's specification (approximately 13 lb-ft).

3. Inspect and Replace Ignition Coil

• If the spark plug is normal, proceed to the ignition coil:
  • If the ignition coil shows signs of damage (cracks, corrosion), it should be replaced.
  • Install a new ignition coil by reversing the removal process.
  • Ensure the electrical connector is securely attached.

4. Check Fuel Injector

• If misfire persists, inspect the fuel injector:
  • Use a multimeter to check the resistance of the injector (should be around 12-16 ohms).
  • If it is faulty, remove the fuel injector and replace it with a new one.
• Ensure to clean any debris from the injector port before installation.

5. Test and Reassemble

• Reconnect the battery terminal.
• Start the engine and allow it to reach operating temperature.
• Check for any additional codes using the OBD-II scanner.
• If no codes appear and the engine runs smoothly, reassemble any remaining components.