how to fix the P0420 code on Tesla Model 3 Original (2017-2023)

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is on a level surface and secure it with wheel chocks.
• Disconnect the battery to prevent electrical shorts.

2. Inspect Exhaust System

• Visually inspect the entire exhaust system, including the catalytic converter and exhaust pipes.
• Look for any signs of rust, holes, or leaks.
• Tighten any loose connections and replace damaged sections if necessary.

3. Replace Oxygen Sensors (if faulty)

• Tools Required: O2 sensor socket, torque wrench
• Remove the upstream and downstream oxygen sensors using the O2 sensor socket.
• Install the new sensors and tighten to the manufacturer's specified torque value (typically around 30 lb-ft).
• Reconnect the wiring harness.

4. Replace Catalytic Converter (if damaged)

• Tools Required: Socket set, torque wrench, exhaust gasket
• Remove the exhaust bolts securing the catalytic converter to the exhaust manifold and downstream exhaust.
• Carefully lower the catalytic converter from its position.
• Install the new catalytic converter with a new exhaust gasket, ensuring all bolts are tightened to the specified torque.
• Reconnect all related exhaust components.

5. Clear Codes and Test

• Reconnect the battery.
• Use the OBD-II scanner to clear the P0420 code.
• Start the vehicle and allow it to reach operating temperature.