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

Solution

1. Preparation

• Gather tools and parts required for repair.
• Ensure the vehicle is parked on a level surface and the engine is cool.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Disconnect the vehicle's battery to prevent electrical shorts.
• Locate the upstream and downstream oxygen sensors.
• Using the O2 sensor socket, remove the sensors from the exhaust system.
• Install new oxygen sensors, ensuring they are torqued to the manufacturer's specifications (typically around 30 lb-ft).
• Reconnect the battery.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, jack stands, exhaust pipe cutter (if necessary), torque wrench.
• Raise the vehicle using a jack and secure it with jack stands.
• Inspect the catalytic converter for damage or restrictions.
• If replacement is needed, use the exhaust pipe cutter to remove the old catalytic converter.
• Install the new catalytic converter, ensuring to use new gaskets and follow torque specifications (typically around 30-40 lb-ft for bolts).
• Reconnect any exhaust hangers and ensure there are no leaks.

4. Clear Codes and Test Drive

• Tools Required: OBD-II scanner.
• Use the OBD-II scanner to clear the P0420 code after repairs.
• Test drive the vehicle under various conditions to ensure the code does not reappear.