how to fix P0421 code in Renault Clio V (2019-Present)?

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety while working on electrical components.
• Tools Required: OBD-II scanner, socket set, torque wrench, temperature probe, multimeter.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Use an OBD-II scanner to verify the operation of the upstream and downstream oxygen sensors.
  2. If faulty, remove the oxygen sensors from their respective positions using a socket wrench.
  3. Install new oxygen sensors and torque them to the manufacturer’s specifications (usually 30-50 Nm).
  4. Reconnect electrical connectors to the new sensors.

3. Inspect and Clean Catalytic Converter

• Sub-steps:
  1. If the catalytic converter is accessible, remove it from the exhaust system using a socket set.
  2. Inspect the catalytic converter for any signs of physical damage or clogging.
  3. If it appears clogged but not damaged, clean it with a suitable catalytic converter cleaner.
  4. Reinstall the catalytic converter and ensure all bolts are tightened to the specified torque (usually around 50-70 Nm).

4. Reset the Engine Control Module (ECM)

• Sub-steps:
  1. Reconnect the battery terminals.
  2. Use the OBD-II scanner to clear any stored trouble codes.
  3. Start the engine and allow it to reach operating temperature.