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

Solution

1. Preparation

• Gather tools and parts required.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream and downstream oxygen sensors.
2. Use a socket wrench to carefully remove the oxygen sensors.
3. Inspect the sensors for carbon buildup or damage.
4. If faulty, replace them with new sensors by threading them in and tightening to manufacturer specifications (typically 30 Nm/22 lb-ft).
5. Reconnect the electrical connectors.

3. Inspect and Replace the Catalytic Converter

1. Evaluate the condition of the catalytic converter visually for any signs of physical damage or rattling.
2. If necessary, remove the exhaust pipe sections connected to the catalytic converter using a socket set.
3. Unbolt the catalytic converter from its mounting points and remove it.
4. Install the new catalytic converter by reversing the removal steps. Ensure all gaskets are in place and properly aligned.
5. Tighten the mounting bolts to the specified torque (typically 40 Nm/30 lb-ft).

4. Reconnect Battery and Test

1. Reconnect the negative battery terminal.
2. Start the engine and allow it to reach operating temperature.
3. Monitor for any warning lights and ensure proper operation.