how to diagnose my Tesla Model S Original (2012-2020) with error code P0420

• •Check engine light illuminated
• •Decreased fuel efficiency
• •Poor acceleration or power loss
• •Unusual exhaust smells (e.g., sulfur)
• •Increased emissions during testing

1. 1Scan the vehicle's onboard diagnostics using an OBD-II scanner to confirm the P0420 code.
2. 2Inspect the catalytic converter for physical damage, such as dents, cracks, or signs of overheating.
3. 3Check for exhaust leaks in the system before the catalytic converter, as these can affect readings.
4. 4Verify the operation of the oxygen sensors (upstream and downstream) by checking their voltage output with a multimeter.
5. 5Inspect all related wiring and connectors for damage or corrosion.
6. 6Clear the error codes and conduct a test drive to see if the code returns, noting any symptoms that occur.

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
• •Socket set
• •Oxygen sensor socket
• •Multimeter

• •Catalytic converter
• •Upstream and downstream oxygen sensors (if needed)