how to fix P0420 code in Tesla Model 3 Highland (2024-present)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the battery to ensure safety when working on electrical components.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench set, torque wrench.
• Remove the upstream and downstream oxygen sensors by using the O2 sensor socket.
• Inspect the sensors for damage or excessive wear.
• If necessary, replace them with new sensors, ensuring they are compatible with the Tesla Model 3 Highland.
• Torque the new sensors to the manufacturer’s specifications (typically around 30 lb-ft).

3. Inspect and Clean Catalytic Converter

• Tools Required: Socket set, wire brush, cleaning solution.
• Remove the catalytic converter from the exhaust system using the socket set.
• Inspect for physical damage or clogs. If minor clogs are present, clean using a wire brush and appropriate cleaning solution.
• If severely damaged or clogged, replace the catalytic converter with a new one specific to the Tesla Model 3 Highland.

4. Reassemble and Reconnect

• Reinstall the catalytic converter and oxygen sensors, ensuring all bolts are tightened to manufacturer specifications.
• Reconnect the battery.

5. Clear Error Codes

• Use the OBD-II scanner to clear the P0420 code and any other related codes from the vehicle's computer.