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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the vehicle battery to ensure safety.
• Raise the vehicle using jack stands for proper access to the exhaust system.

2. Inspect and Replace Oxygen Sensors (if necessary)

• Remove the upstream oxygen sensor:

  • Use an oxygen sensor socket and ratchet to unscrew the sensor from the exhaust manifold.
  • Disconnect the wiring harness from the sensor.

• Install the new upstream oxygen sensor:

  • Apply anti-seize compound on the threads of the new sensor.
  • Screw in the new sensor and tighten it to the manufacturer's specified torque (typically around 30 lb-ft).
  • Reconnect the wiring harness.

• Remove the downstream oxygen sensor:

  • Follow the same procedure as for the upstream sensor.

• Install the new downstream oxygen sensor:

  • Repeat the same steps as for the upstream sensor.

3. Inspect and Replace Catalytic Converter (if necessary)

• Remove the old catalytic converter:

  • Unbolt the catalytic converter from the exhaust pipes using a socket set.
  • Carefully remove any hangers or brackets holding the converter in place.

• Install the new catalytic converter:

  • Position the new catalytic converter into place and secure it with the appropriate bolts.
  • Use a torque wrench to tighten bolts to the manufacturer’s specifications (usually around 30-40 lb-ft).

4. Reset the OBD-II System

• Reconnect the vehicle battery.
• Use an OBD-II scanner to clear the P0420 code from the system.

5. Test Drive

• Start the vehicle and allow it to reach operating temperature.
• Perform a test drive to ensure that the check engine light does not reappear.