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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool down before working on the exhaust system.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrench set, multimeter
• Remove the upstream oxygen sensor (pre-catalytic converter) using the O2 sensor socket.
• Inspect the sensor for corrosion or damage; replace if necessary.
• Repeat the process for the downstream oxygen sensor (post-catalytic converter).
• Install new oxygen sensors by threading them into their respective locations and tightening to manufacturer's specifications (usually around 30 lb-ft).

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, exhaust pipe cutter or saw, penetrating oil
• Disconnect the exhaust pipes from the catalytic converter by removing the bolts or clamps.
• Carefully cut the old catalytic converter from the exhaust system, if necessary.
• Install the new catalytic converter, ensuring proper alignment with the exhaust pipes.
• Reattach the exhaust pipes and secure them with new gaskets or clamps, tightening to manufacturer's torque specifications.

4. Reset the Engine Control Module

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0420 code from the ECM.
• Start the engine and allow it to reach operating temperature.