how to fix Renault Clio V (2019-Present) check engine light P0420

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety while working on electrical components.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Remove the upstream and downstream oxygen sensors using the O2 sensor socket.
  • Sub-step 1: Unplug the electrical connectors from both sensors.
  • Sub-step 2: Use the O2 sensor socket to unscrew and remove the sensors.
• Install the new oxygen sensors by reversing the removal steps.
  • Sub-step 3: Torque the sensors to the manufacturer's specification (typically around 30 Nm).

3. Inspect and Replace the Catalytic Converter

• Tools Required: Socket set, cutting tool (if welding is necessary), gasket scraper, torque wrench
• Remove the catalytic converter from the exhaust system.
  • Sub-step 1: Disconnect the exhaust pipes at both the inlet and outlet flanges.
  • Sub-step 2: Remove any mounting bolts or brackets securing the catalytic converter.
• Inspect for physical damage or blockage. If damaged, replace with a new catalytic converter.
  • Sub-step 3: Clean the mounting surfaces with a gasket scraper before installing the new catalytic converter.
  • Sub-step 4: Secure the new catalytic converter with mounting bolts, torque to specification (typically around 25 Nm).

4. Reconnect Battery and Clear Codes

• Reconnect the vehicle's battery.
• Use the OBD-II scanner to clear the check engine light and reset the error codes.