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

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, socket set, torque wrench, exhaust pressure gauge, safety glasses, gloves
• Ensure the vehicle is parked on a flat surface and the engine is cool.

2. Inspect and Replace Oxygen Sensors

1. Disconnect the battery to ensure safety.
2. Locate the upstream and downstream oxygen sensors in the exhaust system.
3. Unplug the electrical connectors from both sensors.
4. Use a socket to remove the sensors from the exhaust pipes.
5. Install the new oxygen sensors (if faulty) and torque them to the manufacturer's specifications (usually around 30 lb-ft).
6. Reconnect the electrical connectors.

3. Inspect and Replace Catalytic Converter

1. If oxygen sensors are functional, inspect the catalytic converter visually for damage or blockage.
2. Remove any heat shields or components obstructing access to the catalytic converter.
3. Use a socket set to unbolt the catalytic converter from the exhaust system.
4. Install the new catalytic converter and bolt it securely, torquing to manufacturer specifications (typically around 40 lb-ft).
5. Reinstall any heat shields or components removed.

4. Clear Error Codes

1. Reconnect the battery.
2. Use the OBD-II scanner to clear the P0420 code from the engine control module (ECM).
3. Conduct a short test drive to ensure the check engine light does not reappear.