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

Solution

1. Preparation

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

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Remove the upstream (pre-catalytic) oxygen sensor.
  • Use an O2 sensor socket to unscrew the sensor.
  • Inspect the sensor for any signs of damage or contamination.
• Install a new upstream oxygen sensor.
  • Torque to manufacturer specifications (typically around 30-40 ft-lbs).
• Repeat for the downstream (post-catalytic) oxygen sensor if necessary.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, wrench set, exhaust pipe cutter (if needed), jack stands, safety goggles.
• Raise the vehicle and support it securely on jack stands.
• Inspect the catalytic converter for physical damage or blockage.
• If replacement is necessary:
  • Disconnect the exhaust pipes from the catalytic converter using the socket set.
  • Cut any rusted or damaged sections if needed.
  • Remove the old catalytic converter.
  • Install the new catalytic converter and reconnect the exhaust pipes.
  • Ensure all connections are tight and leak-free.

4. Clear Error Codes

• Reconnect the battery.
• Use an OBD-II scanner to clear the P0420 code from the vehicle’s computer.
• Start the engine and allow it to reach operating temperature.