how to fix P0420 code on my Renault Clio V (2019-Present)

Solution

1. Preparation

• Tools Required: OBD-II scanner, jack and jack stands, socket set, multimeter, smoke machine (if available).
• Allow the engine to cool before starting work.
• Disconnect the battery to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
2. Disconnect the electrical connectors from both sensors.
3. Use the appropriate socket to remove the oxygen sensors.
4. Install new oxygen sensors in reverse order of removal, ensuring they are torqued to the manufacturer’s specifications (typically around 30 Nm).
5. Reconnect the electrical connectors securely.

3. Inspect and Replace Catalytic Converter (if necessary)

1. Remove the exhaust system components connected to the catalytic converter, including any heat shields and brackets.
2. Use a socket set to unbolt the catalytic converter from the exhaust manifold and the exhaust pipe.
3. Inspect the old catalytic converter for signs of blockage or damage.
4. Install the new catalytic converter by reversing the removal steps, ensuring all bolts are torqued to the manufacturer’s specifications (typically around 40 Nm).
5. Reattach any heat shields or brackets that were removed.

4. Clear Codes and Test Drive

1. Reconnect the battery.
2. Use the OBD-II scanner to clear the P0420 code from the vehicle’s memory.
3. Start the engine and allow it to reach operating temperature.
4. Take the vehicle for a test drive to verify the repair and monitor the check engine light.