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

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, socket set, torque wrench, exhaust temperature gauge.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the negative battery terminal to prevent any electrical shorts.

2. Replace Faulty Oxygen Sensors

1. Locate the upstream and downstream oxygen sensors (O2 sensors) near the catalytic converter.
2. Using a socket wrench, carefully unscrew the faulty O2 sensor.
3. Apply anti-seize compound to the threads of the new O2 sensor and install it by hand, then tighten it to the manufacturer’s specified torque.
4. Reconnect the electrical connector to the new O2 sensor.

3. Inspect and Replace the Catalytic Converter (if necessary)

1. If the catalytic converter is determined to be faulty, prepare to replace it.
2. Detach the exhaust system from the catalytic converter by loosening the bolts using a socket set.
3. Remove any hangers or brackets securing the catalytic converter.
4. Install the new catalytic converter, ensuring proper alignment.
5. Secure it with the original bolts, tightening them to the manufacturer’s torque specifications.

4. Reset the OBD-II System

1. Reconnect the negative battery terminal.
2. Use an OBD-II scanner to clear the P0420 code from the vehicle’s computer.
3. Take the vehicle for a test drive to ensure all systems are functioning correctly.