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

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery to prevent electrical shorts.
• Allow the engine to cool down before proceeding.

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream and downstream oxygen sensors (usually found before and after the catalytic converter).
2. Disconnect the electrical connectors from the sensors.
3. Use an oxygen sensor socket to remove the sensors from the exhaust system.
4. Install the new oxygen sensors by threading them in and tightening them to manufacturer specifications (typically around 30 Nm).
5. Reconnect the electrical connectors to the new sensors.

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

1. Check the catalytic converter for signs of damage or blockage.
2. If replacement is needed, remove the exhaust pipe bolts connecting to the catalytic converter using a socket set.
3. Carefully detach the catalytic converter from the exhaust system.
4. Install the new catalytic converter, ensuring the gaskets are in place to prevent leaks.
5. Tighten the exhaust pipe bolts to the specified torque (usually around 25 Nm).

4. Reconnect Battery and Clear Codes

1. Reconnect the negative battery terminal.
2. Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.