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Home/Cars/Tesla/Model S/Plaid/Refresh (2021-present)/why does my Tesla Model S Original (2012-2020) keep throwing a P0420 error code

why does my Tesla Model S Original (2012-2020) keep throwing a P0420 error code

Tesla Model S Plaid/Refresh (2021-present)

Error Codes
Severity: mediumDifficulty: mediumError Code: P04202-4 hours
3 min read
505 words

Problem Statement

Learn how to diagnose and fix P0420 exhaust system issue in Tesla Model S. Step-by-step guide with diagnostic procedures and repair instructions.

Error Code
P0420
Affected Component
Exhaust System
Estimated Time
2-4 hours

Safety Warnings

  • ⚠Disconnect the battery before working on electrical systems.
  • ⚠Allow the engine to cool before inspecting the exhaust system.

Symptoms

  • •Check engine light illuminated
  • •Decreased fuel economy
  • •Possible loss of power during acceleration
  • •Unusual exhaust odors
  • •Increased emissions

Diagnostic Steps

  1. 1Scan the vehicle's onboard diagnostics using an OBD-II scanner to confirm the error code and check for additional codes.
  2. 2Inspect the exhaust system visually for any signs of leaks or damage, particularly around the catalytic converter and exhaust manifold.
  3. 3Check the oxygen sensors' operation by testing their voltage output with a multimeter while the vehicle is running.
  4. 4Measure the exhaust gas temperature before and after the catalytic converter using an infrared thermometer to assess efficiency.
  5. 5Inspect for any exhaust blockages or restrictions that could affect the flow.

Solution

Solution

1. Preparation

  • Tools Required: OBD-II scanner, multimeter, infrared thermometer, socket set.
  • Allow the vehicle to cool down completely before starting any work to prevent burns.

2. Oxygen Sensor Inspection

  • Disconnect the battery to prevent electrical shock.
  • Locate the upstream and downstream oxygen sensors.
  • Use a multimeter to check the voltage output:
    • For the upstream sensor, the voltage should fluctuate between 0.1V and 0.9V.
    • For the downstream sensor, it should be relatively stable, around 0.5V.
  • If any sensor is out of specification, replace it.

3. Catalytic Converter Inspection

  • If the oxygen sensors are functioning correctly, proceed to inspect the catalytic converter.
  • Remove the heat shields if necessary to access the catalytic converter.
  • Check for any physical damage or signs of clogging.
  • If a physical blockage is found, the catalytic converter will need to be replaced.

4. Exhaust System Check

  • Inspect the entire exhaust system for leaks or damage that could affect the catalytic converter's performance.
  • Tighten or replace any damaged components as necessary.
  • Ensure there are no exhaust leaks upstream of the catalytic converter.

5. Reassembly and Testing

  • Reinstall any components that were removed during inspection.
  • Reconnect the battery.
  • Clear the error codes using the OBD-II scanner.
  • Start the vehicle and monitor for any reoccurrence of the P0420 code.

Verification

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

Prevention Tips

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

Tools & Equipment Required

  • •OBD-II scanner
  • •Multimeter
  • •Infrared thermometer
  • •Socket set

Parts Required

  • •Oxygen sensors (if faulty)
  • •Catalytic converter (if damaged)

Additional Information

Error Code
P0420
Affected Component
Exhaust System
Estimated Time
2-4 hours
Difficulty
medium
Severity
medium
Tools Required
4 items
Parts Required
2 items

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