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

Solution

1. Preparation

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

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  • Locate the upstream and downstream oxygen sensors.
  • Remove the electrical connectors and unbolt the sensors using a suitable socket.
  • Install the new oxygen sensors (ensure to use the correct torque specifications as per manufacturer’s guidelines).
  • Reconnect the electrical connectors.
• Tools Required: Oxygen sensor socket, ratchet, torque wrench.

3. Inspect and Replace Catalytic Converter

• Sub-steps:
  • Raise the vehicle securely on jack stands.
  • Remove any heat shields or components blocking access to the catalytic converter.
  • Unbolt the catalytic converter from the exhaust system using a socket set.
  • Inspect the exhaust pipes for damage or blockages before installing the new catalytic converter.
  • Install the new catalytic converter, ensuring to use new gaskets and bolts as needed (tighten to manufacturer’s specifications).
• Tools Required: Ratchet set, socket set, gaskets.

4. Reset the Engine Control Unit (ECU)

• Sub-steps:
  • Reconnect the battery.
  • Use the OBD-II scanner to clear the P0421 code from the ECU.
• Tools Required: OBD-II scanner.