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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to prevent electrical shock.

2. Inspect and Replace Oxygen Sensors

1. Locate the Oxygen Sensors:

   • The upstream (pre-catalytic) sensor is located before the catalytic converter, and the downstream (post-catalytic) sensor is located after it.

2. Remove the Upstream Oxygen Sensor:

   • Use an oxygen sensor socket to unscrew the upstream sensor.
   • Disconnect the electrical connector.

3. Install the New Upstream Sensor:

   • Apply anti-seize compound to the threads of the new sensor.
   • Screw in the new sensor and connect the electrical harness.

4. Repeat for the Downstream Oxygen Sensor:

   • Follow the same steps for the downstream oxygen sensor if it is also faulty.

3. Inspect and Replace Catalytic Converter (if necessary)

1. Visual Inspection:

   • Check the catalytic converter for physical damage or clogs.
   • Tap lightly with a rubber mallet to listen for rattling sounds.

2. Remove the Old Catalytic Converter:

   • Loosen and remove the bolts or clamps securing the catalytic converter to the exhaust system.
   • Disconnect any sensors attached to it.

3. Install the New Catalytic Converter:

   • Position the new catalytic converter in place.
   • Reattach the bolts/clamps securely, following the manufacturer's torque specifications (typically around 25-35 Nm).
   • Reconnect any sensors.

4. Reset the Engine Control Module (ECM)

• Reconnect the battery.
• Use the OBD-II scanner to clear the P0420 code from the ECM.