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

Solution

1. Preparation

• Gather tools and parts required for repair.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shocks.

2. Replace Faulty Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Sub-steps:
  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  2. Using the O2 sensor socket, carefully unscrew the faulty sensors from their respective locations.
  3. Install the new oxygen sensors, ensuring they are tightened to the manufacturer's torque specifications (typically around 30-40 Nm).
  4. Reconnect the electrical connectors for the oxygen sensors.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Wrench set, jack and jack stands, exhaust hanger removal tool
• Sub-steps:
  1. Raise the vehicle using a jack and secure it with jack stands.
  2. Remove the exhaust hangers using the exhaust hanger removal tool to free the catalytic converter.
  3. Disconnect the bolts securing the catalytic converter to the exhaust manifold and exhaust pipe.
  4. Remove the old catalytic converter and replace it with a new one, ensuring proper alignment.
  5. Reattach the exhaust bolts and hangers, tightening to the specified torque.

4. Reset the Engine Control Module (ECM)

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the trouble codes from the ECM.