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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety while working on electrical components.
• Tools Required: OBD-II scanner, multimeter, socket set, torque wrench, backpressure gauge.

2. Inspect and Replace O2 Sensors

• Inspect Upstream O2 Sensor:
  • Remove the upstream oxygen sensor using a socket.
  • Inspect for dirt or damage; replace if necessary.
• Install New O2 Sensor:
  • Apply anti-seize compound to the threads of the new sensor.
  • Torque the sensor to the manufacturer's specification (typically around 30 ft-lbs).

3. Inspect and Replace Catalytic Converter (if necessary)

• Remove Exhaust Components:
  • Loosen and remove any clamps or bolts securing the exhaust system and catalytic converter.
  • Carefully remove the catalytic converter from the exhaust system.
• Install New Catalytic Converter:
  • Position the new catalytic converter and secure it with new gaskets if required.
  • Torque all bolts to the manufacturer's specifications (refer to service manual for specific torque values).

4. Reconnect Battery and Clear Codes

• Reconnect the battery terminals.
• Use the OBD-II scanner to clear the P0420 code from the ECU.