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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is off.
• Disconnect the battery to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, torque wrench, penetrating oil
• Sub-steps:
  1. Locate the pre-catalytic and post-catalytic oxygen sensors.
  2. Apply penetrating oil to the sensor threads if they are rusted.
  3. Disconnect the electrical connectors for both sensors.
  4. Use the O2 sensor socket to remove the sensors.
  5. Install the new sensors hand-tight, then torque to manufacturer specifications (typically around 30-40 lb-ft).
  6. Reconnect the electrical connectors.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, jack and jack stands, exhaust gasket, torque wrench
• Sub-steps:
  1. Raise the vehicle using a jack and secure with jack stands.
  2. Locate the catalytic converter and inspect for visible damage or clogs.
  3. Remove any heat shields and disconnect the exhaust pipes from the catalytic converter using a socket set.
  4. Remove the catalytic converter by unbolting it from the exhaust manifold and exhaust pipe.
  5. Install the new catalytic converter with a new gasket, ensuring proper alignment with the exhaust system.
  6. Torque bolts to manufacturer specifications (typically around 30-40 lb-ft).
  7. Reattach any heat shields.

4. Reset the Engine Control Module (ECM)

• Tools Required: OBD-II scanner
• Sub-steps:
  1. Reconnect the battery terminals.
  2. Use the OBD-II scanner to clear the P0420 code from the ECM.
  3. Perform a test drive to ensure the code does not return.