my Tesla Model S Original (2012-2020) has a check engine light with code P0420

Learn how to diagnose and fix P0420 catalytic converter efficiency issue in Tesla Model S. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle's battery to prevent electrical issues during repairs.
• Allow the exhaust system to cool before working on it.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench

• Remove the upstream oxygen sensor:

  • Locate the upstream O2 sensor (usually before the catalytic converter).
  • Use the O2 sensor socket and ratchet to unscrew the sensor.
  • Inspect the sensor for damage.

• Install the new upstream oxygen sensor:

  • Apply anti-seize compound to the threads of the new sensor.
  • Install and tighten to the manufacturer’s specified torque (usually around 30 Nm).

• Repeat the process for the downstream oxygen sensor if necessary.

3. Replace the Catalytic Converter (if needed)

• Tools Required: Socket set, torque wrench, exhaust hangers removal tool
• Remove the old catalytic converter:
  • Loosen and remove the bolts securing the catalytic converter to the exhaust system.
  • Carefully detach the converter from its mounts.
  • Check exhaust hangers for wear; replace if necessary.
• Install the new catalytic converter:
  • Position the new converter and reconnect it to the exhaust system.
  • Tighten the bolts to the manufacturer’s specified torque (usually around 40 Nm).

4. Reconnect Battery and Clear Codes

• Reconnect the vehicle’s battery.
• Use the OBD-II scanner to clear the P0420 code and perform a readiness test.