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 engage the parking brake.
• Disconnect the negative terminal of the battery to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors (if necessary)

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Remove the upstream (pre-catalytic converter) oxygen sensor:
  • Locate the sensor on the exhaust manifold.
  • Use the O2 sensor socket to unscrew the sensor carefully.
• Install the new oxygen sensor:
  • Apply anti-seize compound on the threads of the new sensor.
  • Torque to manufacturer specifications (typically around 30 lb-ft).
• Repeat for the downstream (post-catalytic converter) oxygen sensor if it shows signs of failure.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, exhaust pipe cutter (if applicable)
• Remove the catalytic converter:
  • Loosen the bolts connecting the catalytic converter to the exhaust system using a socket set.
  • If necessary, use an exhaust pipe cutter to remove the catalytic converter.
• Install the new catalytic converter:
  • Position the new catalytic converter in place.
  • Secure it with bolts and gaskets; torque to manufacturer specifications (typically around 40 lb-ft).

4. Reconnect Battery and Clear Codes

• Reconnect the negative terminal of the battery.
• Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.

5. Test Drive

• Take the vehicle for a test drive to ensure the check engine light does not reappear and monitor performance.