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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety.
• Ensure the vehicle is on a level surface and raise it using jack stands if needed.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench set, multimeter.
• Steps:
  1. Locate the upstream and downstream oxygen sensors.
  2. Disconnect the wiring harness from both sensors.
  3. Use the O2 sensor socket to remove the upstream sensor first.
  4. Inspect the sensor for damage. If faulty, replace it with a new sensor.
  5. Repeat the process for the downstream sensor if needed.
  6. Reconnect the wiring harness to the new sensors.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, cutting tool (if required), exhaust sealant.
• Steps:
  1. Inspect the catalytic converter for visible damage or signs of blockage.
  2. If replacement is needed, remove the exhaust hangers to free the exhaust system.
  3. Use a cutting tool if the converter is welded in place; otherwise, unbolt it from its mounting points.
  4. Install the new catalytic converter, ensuring all gaskets are in place.
  5. Secure it with bolts to the exhaust system.
  6. Reattach any exhaust hangers that were removed.

4. Clear Codes and Test Drive

• Tools Required: OBD-II scanner.
• Steps:
  1. Reconnect the battery.
  2. Use the OBD-II scanner to clear the P0420 code from the system.
  3. Start the engine and allow it to reach operating temperature.
  4. Take the vehicle for a test drive to ensure the check engine light does not reappear.