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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Ensure the vehicle is on a flat surface and securely raised with jack stands.
• Disconnect the vehicle's battery negative terminal.

2. Inspect and Replace Oxygen Sensors

1. Locate the Oxygen Sensors: Identify the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
2. Remove the Sensors: Use an oxygen sensor socket or wrench to carefully unscrew the sensors.
   • Tools Required: Oxygen sensor socket, wrench.
3. Inspect the Sensors: Check for carbon buildup, damage, or corrosion.
4. Install New Sensors: If faulty, replace with new sensors, tightening to manufacturer specifications (usually around 30 ft-lbs).
   • Parts Required: New upstream and downstream oxygen sensors.

3. Inspect and Replace Catalytic Converter (if necessary)

1. Remove Exhaust Components: Detach any bolts or clamps securing the catalytic converter in place.
   • Tools Required: Socket set, wrench.
2. Inspect the Catalytic Converter: Look for signs of damage or excessive carbon buildup.
3. Install New Catalytic Converter: If the converter is faulty, replace it with a new one, ensuring proper alignment and securing it with bolts to the specified torque (usually around 30-40 ft-lbs).
   • Parts Required: New catalytic converter.

4. Reassemble and Reconnect

1. Reconnect Exhaust Components: Reattach any removed exhaust components and ensure all connections are secure.
2. Reconnect Battery: Reattach the negative battery terminal.
3. Check for Leaks: Start the engine and listen for exhaust leaks around newly installed components.