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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle battery to prevent electrical shorts.
• Ensure the vehicle is on a level surface and lift it using a jack and jack stands if needed.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench set, penetrating oil (if needed)
• Sub-steps:
  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  2. Apply penetrating oil to the sensor threads if they are rusted or difficult to remove.
  3. Disconnect the wiring harness from both sensors.
  4. Using the O2 sensor socket, remove both sensors.
  5. Install new sensors by threading them in by hand and then tightening them to the manufacturer's specifications (usually around 30-35 Nm).
  6. Reconnect the wiring harness.

3. Inspect and Replace the Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, exhaust gaskets
• Sub-steps:
  1. Remove the exhaust system components connected to the catalytic converter, including the bolts and any hangers.
  2. Carefully detach the catalytic converter from the exhaust manifold and the exhaust pipe.
  3. Inspect the old catalytic converter for physical damage or clogging; if damaged, replace it with a new unit.
  4. Install the new catalytic converter, ensuring all gaskets are replaced and the bolts are torqued to specifications (typically around 25-30 Nm).
  5. Reconnect any exhaust components removed earlier.

4. Clear Codes and Test Drive

• Tools Required: OBD-II scanner
• Sub-steps:
  1. Reconnect the vehicle battery.
  2. Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.
  3. Start the vehicle and perform a test drive to ensure the check engine light does not reappear.