how to fix P0420 code on my Toyota Camry XV70 (2018-2024)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery to avoid electrical issues.
• Allow the engine to cool before beginning work.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Remove the upstream oxygen sensor using an oxygen sensor socket.
  2. Inspect the sensor for damage; replace if necessary.
  3. Repeat for the downstream oxygen sensor.
  4. Install new oxygen sensors securely, ensuring proper torque (usually 30-40 lb-ft).

Tools Required:

• OBD-II scanner
• Oxygen sensor socket
• Torque wrench

3. Inspect or Replace Catalytic Converter

• Sub-steps:
  1. Visually inspect the catalytic converter for any physical damage or signs of overheating (discoloration).
  2. If damage is found, remove the catalytic converter by unbolting it from the exhaust system.
  3. Install the new catalytic converter, ensuring all gaskets and bolts are appropriately secured (refer to manufacturer specifications for torque).
  4. Reconnect any exhaust components removed during the process.

4. Clear Codes and Test Drive

• Sub-steps:
  1. Reconnect the battery.
  2. Use the OBD-II scanner to clear the P0420 code.
  3. Test drive the vehicle to ensure the check engine light does not reappear and monitor performance.