why is my Toyota Camry XV70 (2018-2024) check engine light on with code P0420

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to prevent any electrical shorts.

2. Oxygen Sensor Replacement (if faulty)

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Locate the faulty oxygen sensor (typically near the catalytic converter).
• Disconnect the electrical connector from the sensor.
• Remove the sensor using the O2 sensor socket.
• Install the new oxygen sensor and torque to manufacturer specifications (usually around 30 ft-lbs).
• Reconnect the electrical connector.

3. Catalytic Converter Inspection/Replacement

• Tools Required: Jack and jack stands, socket set, torque wrench.
• Raise the vehicle securely using a jack and jack stands.
• Inspect the catalytic converter for any visible damage or signs of clogging.
• If replacement is necessary, disconnect the exhaust pipes from the catalytic converter by removing the bolts using a socket set.
• Remove the old catalytic converter.
• Install the new catalytic converter, ensuring proper alignment with the exhaust system and torque bolts to manufacturer specifications (usually around 30-40 ft-lbs).

4. Reconnect Battery and Clear Codes

• Reconnect the battery terminals.
• Use an OBD-II scanner to clear the trouble codes from the vehicle's memory.
• Start the engine and allow it to reach operating temperature.