how to fix P0420 code on Tesla Model S Original (2012-2020)

Learn how to diagnose and fix P0420 exhaust system issue in Tesla Model S (2012-2020). Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative battery terminal to avoid electrical shorts.
• Allow the vehicle to cool down as the exhaust system can be hot.

2. Inspect and Replace O2 Sensors

1. Locate the O2 Sensors: Identify the upstream (pre-catalytic converter) and downstream (post-catalytic converter) O2 sensors.
2. Disconnect the Sensors: Carefully unplug the electrical connectors from both O2 sensors.
3. Remove the Sensors: Use an O2 sensor socket to remove each sensor from the exhaust system.
4. Install New Sensors: Apply anti-seize compound on the threads of the new O2 sensors and install them in the same locations as the old ones. Tighten to manufacturer's specifications.
5. Reconnect Electrical Connectors: Plug the electrical connectors back into the new O2 sensors.

3. Inspect and Replace the Catalytic Converter (if necessary)

1. Visual Inspection: Examine the catalytic converter for cracks, dents, or signs of overheating.
2. Check for Restrictions: Remove the exhaust pipe connected to the catalytic converter and check for clogs or restrictions by looking inside the converter.
3. Remove the Catalytic Converter: If replacement is necessary, unbolt the catalytic converter from the exhaust system using a socket set.
4. Install New Catalytic Converter: Position the new catalytic converter and secure it with bolts. Ensure all gaskets are in good condition and replace if necessary.
5. Reconnect Exhaust System: Reattach any exhaust piping removed during the process, ensuring a tight fit to prevent leaks.

4. Clear Codes and Test

1. Reconnect the Battery: Reconnect the negative battery terminal.
2. Clear Error Codes: Use the OBD-II scanner to clear the P0420 code.
3. Test Drive the Vehicle: Drive the vehicle under various conditions to ensure the code does not reappear and the vehicle operates normally.