how to fix P0420 code on my Toyota RAV4 XA50 (2019-2024)

Solution

1. Preparation

• Gather tools and parts. Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative terminal of the battery to prevent electrical shock.

2. Inspect and Replace Oxygen Sensors

• Remove the upstream oxygen sensor:
  1. Locate the upstream O2 sensor (before the catalytic converter).
  2. Use an O2 sensor socket to unscrew the sensor.
  3. Inspect the sensor for damage or carbon buildup.
  4. Replace with a new sensor if necessary.
• Repeat for the downstream O2 sensor (after the catalytic converter) if it shows signs of malfunction.

3. Inspect and Replace the Catalytic Converter

• Remove the catalytic converter:
  1. Use a socket set to unbolt the exhaust pipe at both ends of the catalytic converter.
  2. Carefully detach the converter from the exhaust system.
  3. Inspect for physical damage or blockage.
  4. Replace with a new catalytic converter if necessary, ensuring proper fitment and alignment.
• Reconnect the exhaust pipe and tighten bolts to the manufacturer's torque specifications.

4. Clear the Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0420 code and any other stored codes.
• Start the engine and allow it to reach operating temperature.