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Home/Cars/Ford/Explorer/Fifth Generation (2011-2019)/how to fix P0420 code in Ford Explorer Fifth Generation (2011-2019)

how to fix P0420 code in Ford Explorer Fifth Generation (2011-2019)

Ford Explorer Fifth Generation (2011-2019)

Severity: highDifficulty: mediumError Code: P04202-4 hours
3 min read
533 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 catalytic converter issues in Ford Explorer (2011-2019). Step-by-step guide with symptoms, diagnostic steps, and repair instructions.

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

Safety Warnings

  • ⚠Disconnect the battery before working on electrical components.
  • ⚠Allow the exhaust system to cool before handling components to avoid burns.

Symptoms

  • •Check engine light illuminated
  • •Decreased engine performance
  • •Poor fuel economy
  • •Failed emissions test
  • •Rattling noise from the catalytic converter
  • •Sulfur smell from exhaust

Diagnostic Steps

  1. 1Scan for error codes using an OBD-II scanner to confirm P0420 and check for any related codes.
  2. 2Inspect the exhaust system for leaks or damage, particularly around the catalytic converter.
  3. 3Check the condition of the oxygen sensors before and after the catalytic converter for proper operation.
  4. 4Measure the voltage output of the upstream and downstream oxygen sensors using a multimeter.
  5. 5Inspect the catalytic converter visually for signs of damage, blockage, or excessive carbon buildup.
  6. 6Verify the engine is operating within normal temperature ranges and check for any engine misfires that could affect the catalytic converter.

Solution

Solution

1. Preparation

  • Gather tools and parts required.
  • Disconnect the battery to ensure safety.
  • Raise the vehicle using a jack and secure with jack stands.

2. Inspect and Replace Oxygen Sensors

  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  2. Use an O2 sensor socket to carefully remove the upstream O2 sensor.
  3. Install the new upstream O2 sensor and tighten it to the manufacturer's specified torque (typically around 30 lb-ft).
  4. Repeat for the downstream O2 sensor if it shows signs of failure.
  5. Reconnect the electrical connectors for both sensors.

3. Inspect and Replace Catalytic Converter

  1. Remove the exhaust pipes connected to the catalytic converter using a socket set.
  2. Unbolt the catalytic converter from the exhaust manifold and the exhaust pipe.
  3. Install the new catalytic converter, ensuring proper fitment.
  4. Torque all bolts to the manufacturer's specifications (typically around 25-30 lb-ft).
  5. Reconnect the exhaust pipes and ensure all seals are properly seated.

4. Clear Error Codes

  1. Reconnect the battery.
  2. Use an OBD-II scanner to clear the P0420 code.
  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
  • Socket set
  • Torque wrench
  • Jack and jack stands
  • Multimeter

Parts Required

  • New upstream oxygen sensor
  • New downstream oxygen sensor (if necessary)
  • New catalytic converter

Additional Information

Error CodeP0420
Component

Exhaust System

Repair Time

2-4 hours

Difficulty

medium

Severity

high

Tools

6 items

Parts

3 items

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