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 turned off.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Locate the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
• Tools Required: O2 sensor socket, wrench set.
• Unplug the wiring harness from both sensors.
• Use the O2 sensor socket to unscrew both sensors from the exhaust manifold and catalytic converter.
• Install new oxygen sensors in reverse order and reconnect the wiring harness.
• Torque the sensors to manufacturer's specifications (typically around 30 lb-ft).

3. Inspect and Replace the Catalytic Converter

• Raise the vehicle using a jack and secure with jack stands.
• Tools Required: Socket set, torque wrench, penetrating oil.
• Inspect the catalytic converter for physical damage or clogging.
• If replacement is necessary:
  • Disconnect the exhaust pipes at both ends of the catalytic converter.
  • Remove any mounting brackets or hangers securing the catalytic converter.
  • Install the new catalytic converter in reverse order of removal, ensuring proper alignment.
  • Torque all bolts to specification (typically between 25-35 lb-ft).

4. Reconnect Battery and Clear Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0420 code and any other stored codes.