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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent electrical shock.
• Allow the engine to cool before starting work on the exhaust system.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, wrenches, multimeter
• Sub-steps:
  1. Disconnect the upstream (pre-catalytic) oxygen sensor connector.
  2. Using the O2 sensor socket, remove the upstream oxygen sensor from the exhaust manifold.
  3. Install the new upstream oxygen sensor and torques to manufacturer specifications (typically around 30 lb-ft).
  4. Repeat for the downstream (post-catalytic) oxygen sensor if necessary.

3. Inspect and Replace the Catalytic Converter

• Tools Required: Socket set, torque wrench, cutting tools (if necessary)
• Sub-steps:
  1. Remove any heat shields covering the catalytic converter.
  2. If necessary, cut the exhaust pipes to access the catalytic converter, ensuring to leave enough material for reinstallation.
  3. Unbolt the catalytic converter from the exhaust system using the socket set.
  4. Install the new catalytic converter, ensuring proper alignment and torque to manufacturer specifications (usually around 25-30 lb-ft).
  5. Reinstall any heat shields and reconnect the exhaust system.

4. Reset the Engine Control Module (ECM)

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