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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface and the parking brake is engaged.
• Disconnect the vehicle's battery to prevent electrical shock.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench set, torque wrench
• Remove the upstream and downstream oxygen sensors using the O2 sensor socket.
• Inspect the sensors for carbon buildup or damage.
• Replace with new, quality OEM oxygen sensors if faulty.
• Torque the new oxygen sensors to the manufacturer’s specifications (typically around 30-40 Nm).

3. Inspect and Replace Catalytic Converter (if needed)

• Tools Required: Socket set, wrench set, exhaust hanger removal tool
• Disconnect the exhaust piping from the catalytic converter.
• Remove any bolts or clamps securing the catalytic converter using the socket set.
• Carefully remove the catalytic converter, taking care not to damage surrounding components.
• Install the new catalytic converter, ensuring proper alignment with exhaust pipes.
• Reattach the exhaust piping, tightening bolts to the manufacturer’s torque specifications.

4. Clear Codes and Reconnect Battery

• Reconnect the battery terminals securely.
• Use the OBD-II scanner to clear the P0420 code and any other stored codes.