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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety.
• Allow the vehicle to cool down before working on the exhaust system.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench, penetrating oil.
• Sub-steps:
  1. Locate and remove the upstream (pre-catalytic) oxygen sensor.
     • Use penetrating oil if the sensor is stuck.
     • Disconnect the electrical connector.
  2. Install the new upstream oxygen sensor.
     • Torque to manufacturer specifications (typically around 30 lb-ft).
  3. Repeat the process for the downstream (post-catalytic) oxygen sensor.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, exhaust hanger removal tool.
• Sub-steps:
  1. Remove any heat shields covering the catalytic converter.
  2. Disconnect the exhaust pipes from the catalytic converter.
  3. Unbolt the catalytic converter from the exhaust manifold and exhaust pipe using the socket set.
  4. Install the new catalytic converter, ensuring proper alignment.
     • Torque bolts to manufacturer specifications (commonly around 40 lb-ft).
  5. Reinstall heat shields if applicable.

4. Clear Codes and Test Drive

• Tools Required: OBD-II scanner.
• Sub-steps:
  1. Reconnect the battery and start the engine.
  2. Use the OBD-II scanner to clear the P0420 code.
  3. Take the vehicle for a test drive to ensure the issue is resolved.