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

Solution

1. Preparation

• Gather necessary tools and parts.
• Park the vehicle on a level surface and engage the parking brake.
• Disconnect the battery to ensure safety while working on electrical components.

2. Inspect and Replace Oxygen Sensors

1. Locate Oxygen Sensors: Identify the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
2. Remove Sensors: Use an oxygen sensor socket to carefully unscrew the sensors from their respective locations. Disconnect the wiring harnesses.
3. Install New Sensors: Apply anti-seize compound to the threads of the new sensors and install them into the exhaust system. Tighten them to the manufacturer’s specifications (usually around 30 lb-ft).
4. Reconnect Wiring: Ensure all wiring harnesses are securely connected.

3. Inspect and Replace Catalytic Converter

1. Remove Exhaust Components: Depending on the design, you may need to remove the exhaust pipe or other components to access the catalytic converter.
2. Inspect Catalytic Converter: Check for physical damage or signs of clogging (e.g., discolored or rattling).
3. Replace Converter: If faulty, remove the old catalytic converter. Install the new unit, ensuring that gaskets are in place and bolt connections are tightened to specified torque (usually 25-30 lb-ft).
4. Reassemble Exhaust: Reattach any components that were removed during disassembly.

4. Reset the Engine Control Module (ECM)

1. Reconnect Battery: Reconnect the negative terminal of the battery.
2. Clear Codes: Use the OBD-II scanner to clear any trouble codes from the ECM.
3. Run the Engine: Start the vehicle and allow it to reach operating temperature.