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

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery to ensure safety during the repair process.

2. Address Any Exhaust Leaks

• Sub-steps:
  1. Use a socket set to remove any heat shields if obstructing access.
  2. Locate the exhaust leak, and use exhaust sealant or replace damaged sections of the exhaust pipe.
  3. Reinstall heat shields and ensure all connections are tight.

3. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
  2. Use an O2 sensor socket to remove the sensors.
  3. Install new oxygen sensors by threading them into the correct positions and tightening to manufacturer specifications (usually around 30 Nm).

4. Replace Catalytic Converter (if necessary)

• Sub-steps:
  1. Disconnect any sensors or wiring harnesses attached to the catalytic converter.
  2. Unbolt the catalytic converter from the exhaust system using the appropriate socket size.
  3. Install the new catalytic converter, ensuring proper alignment and tightening all bolts to manufacturer specifications.
  4. Reconnect any sensors or wiring harnesses.

5. Reset the Engine Control Module (ECM)

• Sub-steps:
  1. Reconnect the battery.
  2. Use an OBD-II scanner to clear the P0420 code from the ECM.
  3. Start the vehicle and allow it to reach operating temperature.