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

Solution

1. Preparation

• Ensure the vehicle is parked on a flat surface.
• Disconnect the battery to prevent any electrical shorts.
• Gather necessary tools and parts.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Remove the upstream (pre-catalytic) oxygen sensor:
  1. Locate the sensor on the exhaust manifold.
  2. Use the O2 sensor socket to unscrew the sensor.
  3. Install the new sensor, ensuring it is tightened to the manufacturer's specification (usually around 30 lb-ft).
• Repeat the process for the downstream (post-catalytic) oxygen sensor if necessary.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, exhaust pipe cutter (if needed), gasket scraper, torque wrench.
• If the catalytic converter is faulty:
  1. Lift the vehicle securely using jack stands.
  2. Disconnect the exhaust system from the catalytic converter.
  3. Remove any mounting bolts using the socket set.
  4. If necessary, use an exhaust pipe cutter to remove the old converter.
  5. Install the new catalytic converter, ensuring it is positioned correctly and all bolts are torqued to specifications (usually around 30-35 lb-ft).
  6. Reconnect the exhaust system.

4. Final Checks

• Reconnect the battery.
• Clear the P0420 code using the OBD-II scanner.
• Start the engine and check for exhaust leaks around the repaired areas.