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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle battery to ensure safety during repairs.
• Tools Required: OBD-II scanner, multimeter, exhaust jack, wrenches, and a temperature gauge.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the pre-catalytic and post-catalytic oxygen sensors.
  2. Disconnect the electrical connectors from both sensors.
  3. Use the appropriate socket to remove the sensors from the exhaust manifold and catalytic converter.
  4. Install new oxygen sensors, applying anti-seize compound to the threads.
  5. Torque the sensors to manufacturer specifications (typically around 30 Nm).
  6. Reconnect the electrical connectors.

3. Inspect and Replace Catalytic Converter (if necessary)

• Sub-steps:
  1. Raise the vehicle using a jack and secure it with jack stands.
  2. Inspect the catalytic converter visually for signs of damage or obstruction.
  3. If replacement is needed, unbolt the catalytic converter from the exhaust system, taking care not to damage surrounding components.
  4. Install the new catalytic converter, ensuring a proper fit.
  5. Torque the bolts to the specified manufacturer values (typically around 40 Nm).
  6. Reconnect any exhaust hangers or brackets removed during the process.

4. Reconnect Battery and Clear Codes

• Sub-steps:
  1. Reconnect the vehicle battery.
  2. Use the OBD-II scanner to clear the P0421 code from the computer.
  3. Start the engine and allow it to reach operating temperature while monitoring the check engine light.