how to fix P0420 code on my Toyota RAV4 Fifth Generation (2019-present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench set.
• Steps:
  1. Locate the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
  2. Disconnect the electrical connectors from both oxygen sensors.
  3. Use the O2 sensor socket to remove the upstream sensor, then repeat for the downstream sensor.
  4. Install the new oxygen sensors, ensuring they are tightened to the manufacturer’s specifications (typically around 30 lb-ft).
  5. Reconnect the electrical connectors to the sensors.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, exhaust pipe cutter (if needed).
• Steps:
  1. Locate the catalytic converter under the vehicle.
  2. Inspect for physical damage; if damaged, proceed to remove it.
  3. Disconnect the exhaust pipes leading to and from the catalytic converter using the socket set.
  4. If necessary, cut the exhaust pipes with an exhaust cutter for easier removal.
  5. Install the new catalytic converter, ensuring all connections are secure and torqued to specifications (typically around 25-30 lb-ft for flange bolts).
  6. Reconnect all exhaust piping and ensure seals are intact.

4. Reset the ECU

• Tools Required: OBD-II scanner.
• Steps:
  1. Reconnect the battery.
  2. Use an OBD-II scanner to clear the P0420 code from the ECU.
  3. Start the engine and allow it to reach operating temperature.