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

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, socket set, torque wrench, exhaust back pressure gauge.
• Ensure the vehicle is parked on a level surface and the engine is turned off.
• Disconnect the battery to avoid electrical shorts during repairs.

2. Oxygen Sensor Replacement

• Tools Required: O2 sensor socket, wrench.
• Remove the oxygen sensor located before the catalytic converter.
  • Sub-step: Use a wrench or O2 sensor socket to unscrew the sensor carefully.
• Install the new oxygen sensor and torque it to the manufacturer’s specifications (typically around 30-40 ft-lbs).
• Reconnect the electrical connector.

3. Catalytic Converter Inspection/Replacement

• Tools Required: Socket set, exhaust hanger tool.
• Disconnect the exhaust system from the catalytic converter.
  • Sub-step: Remove bolts or clamps securing the exhaust pipe to the converter.
• Inspect the catalytic converter for any cracks or blockages.
• If damaged, replace with a new catalytic converter.
  • Sub-step: Install the new catalytic converter and secure it with bolts or clamps, torquing to manufacturer specifications.

4. Final Assembly

• Reconnect the exhaust system and ensure all hangers and connections are secure.
• Reconnect the battery.