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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent any electrical issues.
• Allow the engine to cool if it has been running recently.

2. Inspect and Replace Oxygen Sensors

1. Locate the oxygen sensors: Find the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
2. Remove the upstream oxygen sensor:
   • Use an oxygen sensor socket to unscrew the sensor.
   • Disconnect the electrical connector.
3. Install the new upstream oxygen sensor:
   • Apply anti-seize compound to the threads of the new sensor.
   • Screw in the new sensor and connect the electrical connector.
4. Repeat for the downstream oxygen sensor: Follow the same steps as above for the downstream sensor.

3. Inspect and Replace the Catalytic Converter (if necessary)

1. Remove the catalytic converter:
   • Use a socket set to remove the bolts connecting the catalytic converter to the exhaust system.
   • Carefully detach the catalytic converter from the vehicle.
2. Inspect the catalytic converter: Check for physical damage, such as cracks or excessive carbon buildup.
3. Install the new catalytic converter:
   • Position the new converter in place and secure it with the bolts.
   • Torque the bolts to the manufacturer’s specifications (typically 30-50 lb-ft, but consult the service manual).
4. Reconnect any exhaust hangers that may have been removed during the process.

4. Clear Codes and Test Drive

1. Reconnect the battery and clear the error codes using an OBD-II scanner.
2. Test drive the vehicle to ensure the code does not return and monitor performance.