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

Solution

1. Preparation

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

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream and downstream oxygen sensors.
2. Use a socket wrench to carefully unscrew the sensors from their mounting points.
3. Inspect the sensor connectors for corrosion or damage, and clean or replace as needed.
4. Install new oxygen sensors, ensuring they are properly torqued according to manufacturer specifications (typically around 30-40 Nm).
5. Reconnect the negative battery terminal.

3. Inspect and Replace the Catalytic Converter

1. If the catalytic converter is determined to be faulty, remove any heat shields if applicable.
2. Use a socket set to detach the catalytic converter from the exhaust system.
3. Inspect the exhaust manifold and downstream pipes for damage.
4. Install the new catalytic converter, ensuring proper alignment and sealing.
5. Torque all bolts to the manufacturer’s specifications (usually around 25-35 Nm).
6. Reinstall any heat shields removed during the process.

4. Clear Error Codes

1. Use the OBD-II scanner to clear the P0420 code from the ECU.
2. Perform a short test drive to ensure the check engine light does not reappear.