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

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, multimeter, temperature gauge, ramps or jack stands.
• Ensure that the vehicle is parked on a level surface and the engine is turned off.
• Disconnect the battery's negative terminal to prevent any electrical issues.

2. Inspect and Replace Oxygen Sensors

1. Locate Oxygen Sensors: Identify the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
2. Remove Sensors:
   • Use a socket wrench to unscrew the oxygen sensors from their respective locations.
   • Carefully disconnect the electrical connectors.
3. Install New Sensors:
   • Apply anti-seize compound to the threads of the new sensors.
   • Screw in the new sensors and reconnect the electrical connectors.
   • Torque the sensors according to manufacturer specifications (typically around 30 Nm).

3. Inspect and Replace Catalytic Converter

1. Remove Exhaust Components:
   • If necessary, remove any exhaust heat shields or brackets securing the catalytic converter.
   • Use a socket set to unbolt the catalytic converter from the exhaust manifold and exhaust pipe.
2. Install New Catalytic Converter:
   • Position the new catalytic converter in place.
   • Reattach the exhaust components and tighten the bolts to the manufacturer's torque specifications (usually around 40-50 Nm).
3. Reinstall Heat Shields or Brackets.

4. Reset Engine Control Module (ECM)

1. Reconnect Battery: Reattach the negative terminal of the battery.
2. Clear Codes: Use the OBD-II scanner to clear the P0420 code from the ECM.
3. Start the Engine: Allow it to idle for a few minutes to ensure proper functioning.