how to fix the P0420 code on my Ford Explorer Fifth Generation (2011-2019)

Solution

1. Preparation

• Gather tools and parts needed for repairs.
• Disconnect the negative battery terminal to prevent electrical shorts during repairs.

2. Inspect and Replace O2 Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Remove the upstream O2 sensor (sensor before the catalytic converter) using the O2 sensor socket.
• Install the new upstream O2 sensor and torque it to manufacturer specifications (typically around 30 lb-ft).
• Repeat the process for the downstream O2 sensor (sensor after the catalytic converter) if needed.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, wrench set, torque wrench, exhaust gasket.
• Remove any clamps or bolts securing the catalytic converter to the exhaust system.
• Carefully remove the catalytic converter from its mounting position.
• Inspect the old catalytic converter for signs of damage or clogging; replace if necessary.
• Install the new catalytic converter with a new exhaust gasket and secure it with bolts, torquing to manufacturer specifications.

4. Clear Codes and Test

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.
• Start the engine and allow it to reach operating temperature, then take the vehicle for a test drive to confirm the repair.