how to fix P0420 code on Toyota RAV4 Fourth Generation (2013-2018)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety during repairs.

Tools Required:

• OBD-II scanner
• Multimeter
• Infrared thermometer
• Socket set
• Torque wrench
• Jack and jack stands

2. Inspect and Replace Oxygen Sensors (if faulty)

• Check the front and rear oxygen sensors:
  • Using the multimeter, set to voltage mode, measure the voltage output of both sensors.
  • If the readings are outside the manufacturer's specified range, replace the faulty sensor.
• To replace the sensor:
  • Disconnect the electrical connector.
  • Use a socket to unscrew the sensor from the exhaust pipe.
  • Install the new sensor and torque it to the manufacturer's specifications (typically around 30 lb-ft).
  • Reconnect the electrical connector.

3. Inspect and Replace Catalytic Converter (if necessary)

• Inspect the catalytic converter:
  • Check for physical damage or a rattling sound.
• If replacement is needed:
  • Raise the vehicle and secure it with jack stands.
  • Unbolt the catalytic converter from the exhaust system using the socket set (note the location of gaskets).
  • Remove the old catalytic converter and replace with a new one, ensuring to use new gaskets.
  • Torque all bolts to the manufacturer's specifications (typically around 30-40 lb-ft).

4. Address Exhaust Leaks

• Locate any leaks:
  • Use a smoke machine or soapy water to find leaks in the exhaust system.
• Repair any leaks found:
  • Tighten connections, replace gaskets, or weld cracks as needed.

5. Final Checks

• Reconnect the battery and clear the P0420 code using the OBD-II scanner.
• Test drive the vehicle for approximately 20 minutes to allow the ECM to reassess the system.