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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent electrical shorts.
• Allow the exhaust system to cool before working.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Remove the upstream oxygen sensor (before the catalytic converter).
  • Use the O2 sensor socket to unscrew the sensor.
  • Disconnect the electrical connector.
• Install the new upstream oxygen sensor.
  • Torque to manufacturer's specification (typically around 30 lb-ft).
• Repeat the process for the downstream oxygen sensor (after the catalytic converter).

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, exhaust hanger removal tool.
• Remove the exhaust pipe connected to the catalytic converter.
  • Use a socket set to unbolt the flanges.
  • Remove any necessary exhaust hangers.
• Inspect the catalytic converter for signs of damage or clogging.
• If replacement is needed, install the new catalytic converter.
  • Align the exhaust flanges and secure with bolts.
  • Torque bolts to manufacturer's specifications.
• Reattach exhaust hangers and ensure everything is secure.

4. Clear Codes and Test

• Reconnect the battery.
• Use the OBD-II scanner to clear the P0420 code.
• Start the engine and let it reach operating temperature.
• Take the vehicle for a test drive to ensure the check engine light remains off.