how to fix P0420 code Toyota Camry Eighth Generation (2018-present)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to ensure safety while working on the vehicle.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Remove the oxygen sensor harness connectors.
  2. Using an O2 sensor socket, remove the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  3. Install new oxygen sensors, ensuring proper torque (typically around 30 lb-ft).
  4. Reconnect the harness connectors securely.

3. Inspect and Replace the Catalytic Converter

• Sub-steps:
  1. Raise the vehicle using a jack and secure it with jack stands.
  2. Remove any heat shields or brackets securing the catalytic converter.
  3. Disconnect the exhaust pipes from the catalytic converter using a socket set, noting the orientation for reassembly.
  4. Remove the catalytic converter bolts and slide the converter off.
  5. Install the new catalytic converter, ensuring all gaskets and mounting hardware are in good condition.
  6. Torque the bolts to manufacturer specifications (typically around 30 lb-ft).
  7. Reattach any heat shields or brackets.

4. Reconnect Battery and Clear Codes

• Sub-steps:
  1. Reconnect the negative battery terminal.
  2. Use an OBD-II scanner to clear the P0420 code.
  3. Start the engine and allow it to reach operating temperature.