how to diagnose a P0420 code in Tesla Model S Original (2012-2020)

• •Check engine light illuminated
• •Decreased fuel efficiency
• •Poor acceleration
• •Unusual exhaust smell (sulfur or rotten egg)
• •Engine misfires
• •Emissions test failure

1. 1Scan for error codes using an OBD-II scanner to confirm the P0420 code and check for any additional codes.
2. 2Inspect the exhaust system visually for obvious signs of damage, leaks, or corrosion.
3. 3Check the oxygen sensors functionality by monitoring their voltage output while the engine is running.
4. 4Conduct a catalytic converter temperature test by measuring the inlet and outlet temperatures of the converter; significant temperature differences indicate a problem.
5. 5Perform a fuel trim analysis to detect if the air-fuel mixture is excessively rich or lean.
6. 6Examine the wiring and connectors related to the oxygen sensors for signs of damage or corrosion.

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
• •Wrench set
• •Torque wrench
• •Exhaust hanger tool

• •Oxygen sensors (upstream and downstream)
• •Catalytic converter (if found faulty)