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

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, multimeter, torque wrench, jack and jack stands.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to prevent electrical issues.

2. Inspect and Replace Oxygen Sensors

1. Locate the oxygen sensors: Identify the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
2. Remove the sensors: Use a socket or wrench to carefully unscrew the sensors from their locations.
3. Test the sensors: Use a multimeter to check the resistance and voltage output of the sensors. Replace any that are out of spec.
4. Install new sensors: Apply anti-seize lubricant to the threads of the new sensors and install them, torquing them to manufacturer's specifications (usually around 30 lb-ft).

3. Inspect and Replace Catalytic Converter

1. Check for damage: Inspect the catalytic converter for signs of physical damage or excessive carbon buildup.
2. Remove the catalytic converter: Use a socket set to unbolt the catalytic converter from the exhaust system. Be prepared for potential rust or corrosion.
3. Install new catalytic converter: Position the new catalytic converter in place, securing it with bolts to the exhaust system. Torque the bolts to specifications (typically around 30 lb-ft).
4. Reconnect exhaust: Ensure all exhaust components are properly aligned and bolted.

4. Clear Codes and Test

1. Reconnect the battery: After all repairs, reconnect the battery.
2. Clear the OBD-II codes: Use the OBD-II scanner to clear the P0420 code.
3. Test drive the vehicle: Take the vehicle for a test drive to ensure the issue is resolved and monitor the check engine light.