how to fix P0420 code on Tesla Model 3 Original (2017-2023)

Solution

1. Preparation

• Gather tools and parts.
• Disconnect the 12V battery to prevent electrical shock.
• Allow the vehicle to cool down if it has been running.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Remove the upstream (pre-catalytic converter) oxygen sensor:
  1. Use the O2 sensor socket to unscrew the sensor from the exhaust.
  2. Inspect the sensor for damage or contamination; replace if necessary.
• Remove the downstream (post-catalytic converter) oxygen sensor:
  1. Repeat the process for the downstream sensor.
  2. Inspect and replace if it shows signs of wear or failure.
• Torque the new sensors to the manufacturer's specifications (typically around 30 Nm).

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, torque wrench, exhaust gasket.
• Raise the vehicle safely using jack stands.
• Remove any heat shields or brackets that obstruct access to the catalytic converter.
• Unbolt and remove the old catalytic converter.
  1. Ensure to collect any necessary gaskets or fittings.
  2. Inspect the exhaust pipes for any damage or corrosion.
• Install the new catalytic converter:
  1. Align it with the exhaust system.
  2. Bolt it in place and torque to manufacturer specifications (usually around 40-50 Nm).
• Reinstall any heat shields or brackets.

4. Reconnect Battery and Clear Codes

• Reconnect the 12V battery.
• Use the OBD-II scanner to clear the P0420 code from the computer.
• Monitor the vehicle for any reoccurrence of the code.