how to fix P0420 code on Ford Explorer Sixth Generation (2020-present)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, and torque wrench.
• Remove the oxygen sensor located upstream (pre-catalytic converter) and downstream (post-catalytic converter).
• Inspect the sensors for damage or contamination, and replace if necessary.
• Torque the new sensors to the manufacturer's specifications (typically 30-40 lb-ft).

3. Inspect and Repair Exhaust System

• Tools Required: Wrench set, exhaust sealant (if needed).
• Visually inspect the exhaust system for leaks, cracks, or loose connections.
• Tighten any loose connections and replace damaged sections of the exhaust pipe.
• Use exhaust sealant to repair minor leaks as needed.

4. Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, cutting tool (if required).
• Remove the bolts securing the catalytic converter to the exhaust system using a socket set.
• Carefully detach the catalytic converter from the exhaust system.
• Install the new catalytic converter, ensuring proper alignment with the exhaust system.
• Torque the bolts to the manufacturer's specifications (typically 30-50 lb-ft).

5. Reconnect Battery and Clear Codes

• Reconnect the negative battery terminal.
• 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.