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

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

Solution

1. Preparation

• Ensure the vehicle is parked on a flat surface and engage the parking brake.
• Disconnect the negative terminal of the battery to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

1. Locate the Oxygen Sensors:

   • Identify the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.

2. Remove the Oxygen Sensors:

   • Use an oxygen sensor socket to carefully unscrew both sensors from their respective locations.

3. Inspect the Sensors:

   • Check for any signs of damage or fouling on the sensors. Replace if necessary.

4. Install New Oxygen Sensors:

   • Apply anti-seize compound on the threads of new sensors and install them, tightening to manufacturer specifications (typically around 30 Nm).

3. Inspect and Replace the Catalytic Converter

1. Remove Exhaust Components:

   • If the catalytic converter is suspected, remove any exhaust pipes connected to it using a socket set.

2. Inspect the Catalytic Converter:

   • Check for physical damage, excessive rust, or blockage.
   • If the unit is damaged, it will need replacement.

3. Install New Catalytic Converter:

   • Position the new catalytic converter and secure it with bolts. Ensure all gaskets are replaced for a proper seal.

4. Reconnect Exhaust Components:

   • Reattach any exhaust pipes removed earlier, tightening the bolts to manufacturer specifications.

4. Reset the ECU

1. Reconnect the Battery:

   • Reconnect the negative battery terminal securely.

2. Clear Error Codes:

   • Use the OBD-II scanner to clear the P0420 code from the ECU and reset any adaptive learning.