how do I troubleshoot a P0420 code on my Tesla Outback 5th Generation (2015-2019)

Solution

1. Preparation

• Gather tools: OBD-II scanner, multimeter, infrared thermometer, socket set, torque wrench, and safety goggles.
• Ensure the vehicle is parked on a level surface, and the parking brake is engaged.

2. Inspect and Replace Oxygen Sensors (if faulty)

1. Locate the oxygen sensors: Identify upstream and downstream sensors in the exhaust system.
2. Disconnect the electrical connectors: Carefully unclip the connectors from each sensor.
3. Test the sensors: Use a multimeter to measure the voltage output; it should fluctuate between 0.1V and 0.9V.
   • If the readings are outside this range, replace the sensor.
4. Remove the faulty sensor: Use an oxygen sensor socket to unscrew and remove the sensor from the exhaust system.
5. Install the new sensor: Thread the new sensor in by hand, then tighten it to the manufacturer's torque specification (usually around 30-35 ft-lbs).
6. Reconnect the electrical connectors: Ensure all connections are secure.

3. Inspect and Replace Catalytic Converter (if necessary)

1. Check for blockages: Use an infrared thermometer to measure the temperature before and after the catalytic converter. The outlet should be significantly hotter (about 100°F higher).
2. Remove the exhaust components: Unbolt any heat shields, oxygen sensors, and exhaust pipes connected to the catalytic converter.
3. Replace the catalytic converter: Install the new unit, ensuring it is properly aligned and secured to the exhaust system.
4. Reattach all components: Bolt the exhaust pipes and heat shields back into place, ensuring to follow torque specifications.