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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the vehicle battery to prevent electrical shorts.
• Raise the vehicle securely on jack stands.

2. Replace Oxygen Sensors (if faulty)

• Tools Required: O2 sensor socket, wrench set, dielectric grease.
• Remove the old oxygen sensors:
  1. Locate the upstream and downstream oxygen sensors.
  2. Use an O2 sensor socket to unscrew and remove the sensors.
• Install the new oxygen sensors:
  1. Apply dielectric grease to the threads of the new sensors.
  2. Screw in the new sensors and tighten them to the manufacturer's specifications (typically around 30 lb-ft).

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, exhaust hanger removal tool, torque wrench, gasket scraper.
• Remove the catalytic converter:
  1. Unbolt the catalytic converter from the exhaust manifold and the exhaust pipe.
  2. Use an exhaust hanger removal tool to detach any hangers.
• Install the new catalytic converter:
  1. Clean the mating surfaces on the exhaust manifold and the exhaust pipe.
  2. Place a new gasket if required and position the new catalytic converter.
  3. Bolt it into place, ensuring to tighten to manufacturer’s torque specifications (typically around 30-40 lb-ft for bolts).

4. Reconnect the Battery and Clear Codes

• Reconnect the vehicle battery.
• Use the OBD-II scanner to clear the P0420 code from the vehicle’s computer.