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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is on a flat surface and the parking brake is engaged.
• Disconnect the negative terminal of the battery to ensure safety.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench set, torque wrench.
• Locate the upstream and downstream oxygen sensors.
• Disconnect the electrical connectors from each sensor.
• Use the O2 sensor socket to remove the sensors from their respective locations.
• Install new oxygen sensors and torque to manufacturer specifications (typically around 30 ft-lbs).
• Reconnect the electrical connectors.

3. Inspect or Replace Catalytic Converter

• Tools Required: Socket set, torque wrench, exhaust pipe cutter (if needed).
• Inspect the catalytic converter for any physical damage or clogs. If damaged, proceed to replace it.
• If replacement is necessary, use the exhaust pipe cutter to remove the old catalytic converter from the exhaust system.
• Install the new catalytic converter, ensuring proper alignment and secure it with the appropriate bolts, torquing to manufacturer specifications.
• Reconnect any exhaust hangers or clamps.

4. Clear Codes and Test

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