my Tesla Outback's check engine light is on with code P0420, what's wrong?

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle's battery to ensure safety while working on electrical components.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors along the exhaust system.
  2. Use a socket wrench to remove the oxygen sensors.
  3. Inspect the sensor connectors for corrosion or damage.
  4. Install new oxygen sensors, ensuring they are properly torqued to manufacturer specifications (typically around 30 lb-ft).
• Tools Required: Oxygen sensor socket, torque wrench, ratchet.

3. Inspect and Replace Catalytic Converter

• Sub-steps:
  1. Remove the exhaust pipes connected to the catalytic converter using a socket set.
  2. Check for any visible damage or blockage in the catalytic converter.
  3. If damaged, install a new catalytic converter, ensuring all gaskets are replaced.
  4. Reconnect the exhaust pipes and torque to manufacturer specifications.
• Tools Required: Socket set, gaskets, replacement catalytic converter.

4. Reconnect Battery and Clear Codes

• Sub-steps:
  1. Reconnect the vehicle's battery.
  2. Use the OBD-II scanner to clear the check engine light codes.
• Tools Required: OBD-II scanner.