how to fix P0420 code in Tesla Outback 4th Generation (2010-2014)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to avoid electrical shorts.

2. Inspect and Test Oxygen Sensors

• Tools Required: OBD-II scanner, multimeter, socket set
• Remove the upstream (pre-catalytic) oxygen sensor using a socket.
• Connect a multimeter to the sensor's terminals and check the voltage output; it should fluctuate between 0.1V to 0.9V.
• If the sensor is not functioning correctly, replace it with a new one.

3. Inspect Catalytic Converter

• Tools Required: Jack and jack stands, wrench set
• Raise the vehicle and secure it on jack stands.
• Visually inspect the catalytic converter for cracks, dents, or signs of overheating.
• If physical damage is found, remove the catalytic converter by unbolting it from the exhaust system.
  • Sub-steps:
    • Use penetrating oil on bolts to ease removal.
    • Support the converter with a jack if necessary.
• Replace with a new catalytic converter if damaged.

4. Reassemble and Reconnect

• Reinstall the oxygen sensors (both upstream and downstream) after the catalytic converter replacement.
• Reconnect the negative battery terminal.
• Ensure all connections are tight and there are no exhaust leaks.