how to troubleshoot P0420 code in Tesla Model S Plaid/Refresh (2021-present)

• •Check engine light illuminated
• •Decreased fuel economy
• •Loss of engine power
• •Unusual exhaust smells (e.g., rotten eggs)
• •Increased emissions
• •Possible engine misfire or rough idle

1. 1Scan the vehicle's OBD-II system using a compatible scanner to confirm the P0420 code and check for any additional codes.
2. 2Inspect the exhaust system visually for any signs of damage, leaks, or loose connections.
3. 3Verify the operation of the oxygen sensors upstream and downstream of the catalytic converter by checking their voltage readings.
4. 4Check for any exhaust leaks between the engine and the catalytic converter, as these can affect readings.
5. 5Examine the condition of the catalytic converter for physical damage or excessive carbon build-up.
6. 6Clear the error codes and take the vehicle for a test drive to see if the P0420 code returns.

After completing the repair, verify that the issue has been resolved:

• ✓Test the affected component to ensure it functions correctly
• ✓Check for any error codes or warning lights
• ✓Monitor the vehicle for a few days to ensure the issue does not recur

To prevent this issue from occurring again:

• •Follow the manufacturer's recommended maintenance schedule
• •Address warning signs early before they develop into major issues
• •Use quality parts and fluids recommended for your vehicle
• •Keep detailed records of all repairs and maintenance

• •OBD-II scanner
• •O2 sensor socket
• •Ratchet
• •Torque wrench
• •Socket set
• •Exhaust pipe cutter

• •Upstream oxygen sensor (if faulty)
• •Downstream oxygen sensor (if faulty)
• •New catalytic converter (if required)