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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to prevent any electrical issues.
• Raise the vehicle securely using jack stands.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench set, penetrating oil.
• If the oxygen sensors are faulty:
  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  2. Apply penetrating oil to the sensor threads and allow it to sit for several minutes.
  3. Disconnect the wiring harness from the sensor.
  4. Use the O2 sensor socket to unscrew and remove the sensor.
  5. Install the new sensor by screwing it in place and reconnecting the wiring harness.
  6. Torque the oxygen sensor to the manufacturer’s specification (typically around 30 ft-lbs).

3. Inspect and Replace the Catalytic Converter

• Tools Required: Socket set, torque wrench, gasket scraper, exhaust sealant.
• If the catalytic converter is faulty:
  1. Remove the exhaust pipe connected to the catalytic converter.
  2. Unbolt the catalytic converter from the exhaust manifold and exhaust pipe using a socket set.
  3. Clean the surfaces where the new converter will be installed using a gasket scraper.
  4. Install the new catalytic converter, ensuring proper alignment with the exhaust system.
  5. Bolt the converter in place and torque to specifications (check manufacturer’s guidelines).
  6. Reconnect the exhaust pipe, ensuring a proper seal with exhaust sealant if needed.

4. Final Checks

• Reconnect the negative battery terminal.
• Clear the code using the OBD-II scanner.
• Start the engine and allow it to reach operating temperature.