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Home/Cars/Subaru/Outback/5th Generation (2015-2019)/how to resolve P0420 code in Tesla Outback 5th Generation (2015-2019)

how to resolve P0420 code in Tesla Outback 5th Generation (2015-2019)

Subaru Outback 5th Generation (2015-2019)

Severity: highDifficulty: mediumError Code: P04202-4 hours
3 min read
564 words

⚠️ Safety Warning

This issue requires immediate attention. If you are not experienced with automotive repairs, consult a professional mechanic. Working on critical systems can be dangerous.

Problem Statement

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

Error Code
P0420
Component
Exhaust System
Repair Time
2-4 hours

Safety Warnings

  • ⚠Disconnect the battery before working on electrical systems.
  • ⚠Allow the exhaust system to cool completely before inspection or repairs.

Symptoms

  • •Check engine light illuminated
  • •Decreased fuel efficiency
  • •Engine misfires
  • •Failed emissions test
  • •Unusual exhaust odors

Diagnostic Steps

  1. 1Scan for error codes using an OBD-II scanner to confirm P0420 and check for any additional codes.
  2. 2Inspect the exhaust system for any visible leaks, damage, or loose connections.
  3. 3Test the oxygen sensors (upstream and downstream) with a multimeter to check for proper voltage and response.
  4. 4Measure the temperature before and after the catalytic converter using an infrared thermometer to assess efficiency.
  5. 5Check for any exhaust restrictions or blockages.
  6. 6Review the vehicle’s service history for prior catalytic converter or oxygen sensor replacements.

Solution

Solution

1. Preparation

  • Gather tools and parts needed for the repair.
  • Ensure the vehicle is parked on a level surface and the engine is cool.
  • Disconnect the battery to prevent electrical shock.

2. Inspect and Replace Oxygen Sensors

  1. Locate the oxygen sensors:
    • The upstream sensor is located in the exhaust manifold or exhaust pipe before the catalytic converter.
    • The downstream sensor is located after the catalytic converter.
  2. Remove the oxygen sensors:
    • Use an oxygen sensor socket to unscrew the sensors from their respective locations.
  3. Install new oxygen sensors:
    • Apply anti-seize compound to the threads of the new sensors.
    • Thread in the new sensors and tighten to manufacturer specifications (typically 30 ft-lbs).
  4. Reconnect the electrical connectors.

3. Inspect and Replace Catalytic Converter (if necessary)

  1. Check the catalytic converter for damage:
    • Look for physical damage or rattling sounds indicating a failed converter.
  2. Remove the catalytic converter:
    • Loosen and remove the bolts or clamps securing the converter to the exhaust system.
    • Carefully detach it from the exhaust pipes.
  3. Install the new catalytic converter:
    • Position the new converter and secure it with bolts or clamps.
    • Ensure all gaskets are replaced to prevent leaks.
  4. Reconnect any exhaust hangers.

4. Reconnect Battery and Clear Codes

  1. Reconnect the negative battery terminal.
  2. Use the OBD-II scanner to clear the P0420 code from the ECM.
  3. Start the engine and allow it to reach operating temperature.

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
  • Oxygen sensor socket
  • Wrench set
  • Torque wrench
  • Infrared thermometer

Parts Required

  • New upstream and downstream oxygen sensors
  • New catalytic converter (if needed)
  • Replacement gaskets and bolts (if necessary)

Additional Information

Error CodeP0420
Component

Exhaust System

Repair Time

2-4 hours

Difficulty

medium

Severity

high

Tools

5 items

Parts

3 items

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