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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool completely before starting work.

2. Inspect and Replace Oxygen Sensors

1. Locate Oxygen Sensors: Identify the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
2. Remove Sensors:
   • Use a socket wrench with an oxygen sensor socket to unscrew the sensors.
   • Carefully disconnect the wiring harness from each sensor.
3. Install New Sensors:
   • Apply anti-seize compound on the threads of the new sensors.
   • Install the new sensors and tighten them to the manufacturer’s specifications (usually around 30 lb-ft).
   • Reconnect the wiring harness.

3. Inspect and Replace Catalytic Converter

1. Remove Exhaust Components:
   • Use a socket set to unbolt the exhaust components around the catalytic converter.
   • Support the exhaust system to prevent sagging.
2. Remove Catalytic Converter:
   • Unbolt the catalytic converter from the exhaust pipes.
   • Carefully take out the old catalytic converter.
3. Install New Catalytic Converter:
   • Position the new catalytic converter in place and secure it with bolts.
   • Ensure all exhaust gaskets are replaced to prevent leaks.

4. Reconnect Battery and Clear Codes

1. Reconnect Battery: Reattach the negative battery terminal.
2. Clear Engine Codes: Use the OBD-II scanner to clear the P0420 code and any other stored codes.