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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle battery to prevent electrical shorts.
• Allow the vehicle to cool before beginning work.

2. Inspect and Replace Oxygen Sensors

1. Locate the oxygen sensors: Identify the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
2. Remove the sensors: Use an oxygen sensor socket to carefully unscrew each sensor from the exhaust system.
3. Inspect and test: Check the wiring for damage and test the sensors with a multimeter to ensure they meet specifications.
4. Install new sensors: If faulty, replace with OEM or quality aftermarket sensors, ensuring proper torque (typically 30-35 ft-lbs).

3. Inspect and Replace the Catalytic Converter

1. Access the catalytic converter: Lift the vehicle and secure it on jack stands.
2. Remove exhaust components: Detach any bolts or clamps securing the catalytic converter to the exhaust system.
3. Inspect the converter: Check for physical damage or clogging; if damaged, replace with an OEM catalytic converter.
4. Install new converter: Position the new catalytic converter, ensuring proper alignment, and secure with bolts or clamps to the manufacturer’s torque specifications.

4. Clear Codes and Test Drive

1. Reconnect the battery: Ensure all connections are secure.
2. Clear the P0420 code: Use the OBD-II scanner to reset the trouble codes.
3. Test drive the vehicle: Drive under various conditions to allow the vehicle to enter closed-loop mode and recheck for codes.