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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Tools Required: OBD-II scanner, socket set, multimeter, jack and jack stands, safety glasses, gloves.
• Safety Warnings: Disconnect the battery before working on electrical systems. Allow the exhaust system to cool before touching it.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  2. Disconnect the electrical connectors from both oxygen sensors.
  3. Use a socket wrench to remove the oxygen sensors from the exhaust system.
  4. Install new oxygen sensors, ensuring they are torqued to manufacturer specifications (usually around 30 lb-ft).
  5. Reconnect the electrical connectors to the new sensors.

3. Inspect and Replace the Catalytic Converter

• Sub-steps:
  1. Raise the vehicle with a jack and secure it on jack stands.
  2. Locate the catalytic converter and check for visible damage.
  3. If replacement is necessary, disconnect the exhaust pipes from the catalytic converter using a socket set.
  4. Remove the old catalytic converter and install the new one, ensuring proper alignment.
  5. Reattach the exhaust pipes and secure with new gaskets or clamps as required.
  6. Lower the vehicle and reconnect the battery.

4. Clear Codes and Test

• Sub-steps:
  1. Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.
  2. Start the engine and let it reach operating temperature.
  3. Take the vehicle for a test drive to monitor performance and ensure no new codes appear.