how to fix P0420 code in Skoda Octavia NFL (2020-Present)

Solution

1. Preparation

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

2. Inspect and Test Oxygen Sensors

• Tools Required: OBD-II scanner, multimeter
• Use the OBD-II scanner to check the live data from the oxygen sensors.
• If the upstream sensor shows abnormal readings, replace the oxygen sensor.

3. Inspect Catalytic Converter

• Tools Required: Jack, jack stands, socket set
• Lift the vehicle safely using a jack and secure it with jack stands.
• Inspect the catalytic converter for any signs of physical damage or obstruction.
• If damaged, proceed to replace the catalytic converter.

4. Replace the Catalytic Converter (if necessary)

• Parts Required: New catalytic converter
• Remove the bolts securing the catalytic converter to the exhaust system.
• Detach the catalytic converter from the exhaust pipes.
• Install the new catalytic converter and secure it using new gaskets and bolts, ensuring proper torque (typically around 30-50 lb-ft depending on the model).
• Reconnect any sensors removed during the procedure.

5. Reconnect Battery and Clear Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0420 code and any related codes from the ECM.