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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the parking brake is engaged.
• Disconnect the battery to prevent electrical issues during the repair.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Remove the downstream oxygen sensor (after the catalytic converter) using the O2 sensor socket.
• Inspect the sensor for damage; replace it if necessary.
• Install the new sensor, ensuring it is torqued to manufacturer specifications (usually around 30 lb-ft).

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, exhaust gasket, torque wrench.
• Raise the vehicle securely on jack stands and remove the exhaust system components leading to the catalytic converter.
• Inspect the catalytic converter for signs of damage or clogging.
• Remove the old catalytic converter by unbolting it from the exhaust manifold and the exhaust pipe.
• Install the new catalytic converter with a new exhaust gasket, torquing bolts to manufacturer specifications (usually around 25 lb-ft).

4. Clear Codes and Test

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