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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the vehicle's battery to ensure safety while working on the electrical components.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors.
  2. Use a socket wrench to remove the old oxygen sensors.
  3. Install new oxygen sensors, ensuring they are torqued to the manufacturer specifications (typically around 30-40 ft-lbs).
  4. Reconnect the electrical connectors to the sensors.

3. Check and Replace the Catalytic Converter (if necessary)

• Sub-steps:
  1. Remove the exhaust heat shield to access the catalytic converter.
  2. Use a wrench to unbolt the catalytic converter from the exhaust system.
  3. Inspect the exhaust manifold and pipe connections for any damage.
  4. Install the new catalytic converter, ensuring all gaskets are replaced and connections are secure.
  5. Torque the bolts to the specified manufacturer value.

4. Reset the Engine Control Unit (ECU)

• Sub-steps:
  1. Reconnect the vehicle's battery.
  2. Use the OBD-II scanner to clear the P0420 code from the ECU.
  3. Start the vehicle and monitor for any reoccurrence of the check engine light.