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

Solution

1. Preparation

• Gather tools and materials needed for the repair.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to prevent any electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors in the exhaust system.
  2. Disconnect the wiring harness from each sensor.
  3. Use an oxygen sensor socket to unscrew and remove the faulty oxygen sensors.
  4. Install new oxygen sensors by threading them in and tightening them to the manufacturer's specification (usually around 30 lb-ft).
  5. Reconnect the wiring harness to each sensor.

3. Inspect and Replace Catalytic Converter (if necessary)

• Sub-steps:
  1. If the catalytic converter is damaged or clogged, it must be replaced.
  2. Remove the exhaust pipes connected to the catalytic converter using a socket set.
  3. Unbolt the catalytic converter from the exhaust manifold and any mounting brackets.
  4. Install the new catalytic converter, ensuring proper alignment and sealing.
  5. Reattach the exhaust pipes and tighten all bolts to the recommended torque specification (typically 15-25 lb-ft).

4. Clear Diagnostic Codes

• Sub-steps:
  1. Reconnect the battery.
  2. Use an OBD-II scanner to clear any existing error codes.
  3. Start the engine and let it run for a few minutes to ensure no codes reappear.