how to fix P0420 code on Ford F-150 13th Generation (2015-2020)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool thoroughly before starting work.

2. Inspect and Replace O2 Sensors

• Sub-steps:
  1. Locate the upstream (pre-catalytic converter) and downstream (post-catalytic converter) O2 sensors.
  2. Disconnect the electrical connectors from both O2 sensors.
  3. Use an O2 sensor socket to remove the sensors from the exhaust manifold and catalytic converter.
  4. Install the new O2 sensors by hand-tightening first, then torque to manufacturer specifications (typically around 30 lb-ft).
  5. Reconnect the electrical connectors securely.

3. Replace the Catalytic Converter (if necessary)

• Sub-steps:
  1. Remove any heat shields or brackets securing the catalytic converter.
  2. Unbolt the catalytic converter from the exhaust system using a socket set (note torque specifications for reinstallation).
  3. Inspect the exhaust pipes for damage while the converter is removed.
  4. Install the new catalytic converter, ensuring proper alignment with the exhaust system.
  5. Torque the bolts to manufacturer specifications (typically around 30-40 lb-ft).
  6. Reinstall any heat shields or brackets removed earlier.

4. Reconnect Battery

• Reconnect the negative battery terminal and ensure it is secured.

5. Clear Error Codes

• Use the OBD-II scanner to clear the P0420 code from the vehicle’s computer.