how can I fix the P0420 code on my Tesla Model 3 Highland (2024-present)

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, socket set, torque wrench, exhaust pressure gauge, safety gloves, and safety glasses.
• Safety Warnings: Disconnect the battery before working on electrical systems. Allow the exhaust system to cool before inspection.

2. Inspect and Replace Oxygen Sensors (if faulty)

• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors on the exhaust system.
  2. Disconnect the electrical connectors from the sensors.
  3. Use a socket wrench to remove the sensors from their respective locations.
  4. Install the new oxygen sensors, ensuring they are tightened to the manufacturer's specifications (typically 30 Nm).
  5. Reconnect the electrical connectors.

3. Inspect and Replace Catalytic Converter (if necessary)

• Sub-steps:
  1. Remove the exhaust system components that obstruct access to the catalytic converter.
  2. Unbolt the catalytic converter from the exhaust manifold and the exhaust pipe, noting the orientation of any gaskets.
  3. Install the new catalytic converter, ensuring to use new gaskets if necessary and torque the bolts to the manufacturer's specifications (usually around 40-50 Nm).
  4. Reassemble any removed exhaust components.

4. Clear Error Codes

• Sub-steps:
  1. Reconnect the battery if it was disconnected.
  2. Use the OBD-II scanner to clear the P0420 error code.
  3. Start the vehicle and allow it to reach operating temperature.