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

Solution

1. Preparation

• Gather tools and necessary parts.
• Disconnect the vehicle battery to prevent electrical shorts.
• Lift the vehicle securely on jack stands for access.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Remove the upstream oxygen sensor:
  • Locate the upstream O2 sensor (before the catalytic converter).
  • Use the O2 sensor socket to carefully unscrew it from the exhaust.
• Install the new upstream O2 sensor:
  • Apply anti-seize compound on the threads (if necessary).
  • Screw the new sensor in and tighten to the manufacturer's torque specification (typically around 30 lb-ft).
• Repeat the process for the downstream sensor (after the catalytic converter) if also suspected to be faulty.

3. Inspect and Replace the Catalytic Converter

• Tools Required: Socket set, torque wrench, exhaust pipe cutter (if necessary)
• Remove the catalytic converter:
  • Loosen the exhaust clamps and bolts securing the catalytic converter.
  • Carefully detach it from the exhaust system.
• Install the new catalytic converter:
  • Position the new catalytic converter in place.
  • Secure it using new gaskets and bolts, tightening to the manufacturer's specifications.

4. Final Checks

• Reconnect the battery.
• Clear the P0420 code using an OBD-II scanner.
• Start the engine and let it run for a few minutes to ensure there are no exhaust leaks.