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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the vehicle battery to ensure safety during the repair.
• Allow the engine to cool down before starting work.

2. Inspect Oxygen Sensors

• Tools Required: OBD-II scanner, multimeter
• Remove the electrical connectors from both the upstream (pre-cat) and downstream (post-cat) oxygen sensors.
• Test the sensors using a multimeter to check for proper voltage output (typically 0.1 to 0.9 volts for switching sensors).
• If either sensor is faulty, replace it with a new, compatible unit.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, torque wrench, penetrating oil
• Locate the catalytic converter; it will be situated in the exhaust system.
• Using a socket set, remove the bolts securing the catalytic converter to the exhaust system.
• Carefully detach the catalytic converter and inspect it for physical damage or clogging.
• If it is damaged or not functioning, install a new catalytic converter. Ensure to use a unit that meets OEM specifications.
• Torque the bolts to the manufacturer’s specifications (typically around 25-30 Nm, but check specific values for the Clio V).

4. Clear Codes and Test Drive

• Reconnect the battery and use the OBD-II scanner to clear the P0420 code.
• Start the engine and allow it to reach operating temperature.
• Conduct a test drive under various conditions (city and highway) to ensure the repair was successful.