how to fix P0420 code on my Toyota RAV4 XA40 (2013-2018)

Solution

1. Preparation

• Gather tools and parts needed for repair.
• Safety gear: gloves and safety glasses.
• Ensure the vehicle is on a flat surface and the engine is cool.

2. Inspect and Replace Oxygen Sensors

1. Remove the upstream (pre-cat) oxygen sensor:
   • Disconnect the sensor’s electrical connector.
   • Use an oxygen sensor socket or wrench to unscrew the sensor.
2. Install the new upstream oxygen sensor:
   • Apply anti-seize compound to the threads of the new sensor (if required).
   • Hand-tighten the sensor and then tighten it to the manufacturer's specifications (usually around 30 ft-lbs).
   • Reconnect the electrical connector.
3. Repeat for the downstream (post-cat) oxygen sensor if necessary, following the same procedure.

3. Inspect and Replace the Catalytic Converter

1. Remove the old catalytic converter:
   • Use a socket set to unbolt the exhaust flanges connecting the catalytic converter to the exhaust system.
   • If applicable, remove any mounting brackets or heat shields.
2. Install the new catalytic converter:
   • Position the new converter and align it with the exhaust flanges.
   • Bolt the converter in place, ensuring all connections are secure and torque to the manufacturer’s specifications (typically around 25-35 ft-lbs).
3. Reinstall any brackets or heat shields removed during the process.

4. Clear the Code and Test

1. Reconnect the battery (if disconnected).
2. Clear the P0420 code using the OBD-II scanner.
3. Start the engine and let it reach operating temperature.
4. Conduct a test drive to ensure that the check engine light does not reappear.