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

Solution

1. Preparation

• Gather tools and parts.
• Disconnect the battery to avoid any electrical issues.
• Secure the vehicle on a flat surface and use jack stands if needed.

2. Inspect and Replace Oxygen Sensors

• Remove the upstream (pre-catalytic) oxygen sensor using an O2 sensor socket.
• Inspect the sensor's condition; replace if faulty.
• Repeat the process for the downstream (post-catalytic) oxygen sensor.
• Install new sensors and torque them to manufacturer specifications (typically around 30 lb-ft).

3. Inspect and Replace the Catalytic Converter

• If the catalytic converter is damaged or clogged, remove it by:
  • Loosening the exhaust bolts connecting it to the exhaust system (use penetrating oil if necessary).
  • Detach any hangers or brackets supporting the converter.
• Install the new catalytic converter, ensuring it is aligned properly.
• Torque the bolts to manufacturer specifications (typically around 40 lb-ft).

4. Reconnect Battery and Clear Codes

• Reconnect the battery terminals.
• Use an OBD-II scanner to clear the P0420 code from the system.

5. Test Drive the Vehicle

• Drive the vehicle for at least 20-30 minutes under various conditions (highway and city driving) to allow the vehicle to complete readiness tests.