why does my Tesla Outback check engine light keep coming on for P0420

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, multimeter, exhaust leak detector.
• Ensure the vehicle is on a level surface and allow the engine to cool.
• Disconnect the battery to ensure safety while working on electrical components.

2. Inspect and Replace O2 Sensors

• Sub-steps:
  1. Locate the upstream and downstream O2 sensors on the exhaust manifold and catalytic converter.
  2. Use a socket to carefully remove the sensors.
  3. Inspect the sensors for corrosion or damage.
  4. If faulty, install new O2 sensors, ensuring to apply anti-seize lubricant on the threads.
  5. Torque the sensors to the manufacturer’s specifications (usually around 30 lb-ft).

3. Examine and Replace Catalytic Converter (if necessary)

• Sub-steps:
  1. Visually inspect the catalytic converter for physical damage or blockage.
  2. If replacement is required, unbolt the flanges connecting the catalytic converter to the exhaust system.
  3. Remove the old catalytic converter and clean the mating surfaces on the exhaust pipes.
  4. Install the new catalytic converter and secure it with bolts, torquing to specifications.
  5. Reconnect any sensors or components that were disconnected during removal.

4. Reconnect Battery and Clear Codes

• Reconnect the battery terminals.
• Use the OBD-II scanner to clear the P0420 code from the vehicle’s computer.