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

Solution

1. Preparation

• Gather tools and parts needed for repair.
• Disconnect the battery to ensure safety during repairs.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench set, multimeter
• Remove the upstream oxygen sensor:
  • Locate the sensor before the catalytic converter.
  • Use an O2 sensor socket to unscrew it from the exhaust pipe.
• Install the new upstream oxygen sensor:
  • Apply anti-seize compound on the threads of the new sensor.
  • Screw it in and tighten it to manufacturer specifications (usually around 30 ft-lbs).
• Repeat for the downstream oxygen sensor if faulty.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, jack and jack stands, exhaust hanger tool
• Raise the vehicle securely on jack stands.
• Remove exhaust hangers using the exhaust hanger tool to free the catalytic converter.
• Unscrew the bolts securing the catalytic converter to the exhaust system and remove it.
• Install the new catalytic converter:
  • Align it properly and secure it with new gaskets and bolts.
  • Torque the bolts to manufacturer specifications (usually around 30-40 ft-lbs).

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.