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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the battery to ensure safety during repairs.
• Raise the vehicle on jack stands to access the exhaust system.

2. Inspect and Replace Oxygen Sensors (if faulty)

• Tools Required: O2 sensor socket, wrench set, multimeter
• Remove the upstream oxygen sensor by using the O2 sensor socket and wrench.
• Inspect the sensor for corrosion or damage; if damaged, replace with a new sensor (ensure it matches OEM specifications).
• Reinstall the new oxygen sensor and torque it to the manufacturer’s specified value (typically around 30-40 Nm).
• Repeat the process for the downstream oxygen sensor if it was also found to be faulty.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, exhaust hanger removal tool
• Disconnect the exhaust pipe from the catalytic converter by removing the bolts with a socket set.
• Remove any exhaust hangers using the exhaust hanger removal tool to free the catalytic converter.
• Inspect the catalytic converter for physical damage or blockage. If damaged, replace it with a new catalytic converter.
• Install the new catalytic converter, ensuring all gaskets are in place, and torque the bolts to the manufacturer’s specified value (typically around 35-50 Nm).
• Reattach any exhaust hangers.

4. Clear Codes and Test

• Reconnect the battery.
• Use the OBD-II scanner to clear the P0420 code and any other related codes.
• Start the engine and allow it to reach operating temperature.