how to fix P0420 code in Ford Explorer Fifth Generation (2011-2019)

Solution

1. Preparation

• Gather tools and parts required.
• Disconnect the battery to ensure safety while working on electrical components.

2. Inspect and Repair Exhaust Leaks

• Sub-steps:
  1. Visually inspect the exhaust system from the engine to the tailpipe.
  2. Use a smoke machine or spray water around joints and seams to detect leaks.
  3. If leaks are found, repair or replace damaged sections of the exhaust system.
• Tools Required: Socket set, exhaust sealant or replacement pipes as needed.

3. Test and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors (usually found in the exhaust manifold and after the catalytic converter).
  2. Disconnect the electrical connectors from the sensors.
  3. Use a wrench to remove the sensors and install new ones.
  4. Connect the electrical connectors securely.
• Tools Required: Oxygen sensor socket, ratchet, and wrench.

4. Inspect and Replace Catalytic Converter (if necessary)

• Sub-steps:
  1. Remove the exhaust pipe connected to the catalytic converter using appropriate tools.
  2. Inspect the catalytic converter for any signs of damage or clogging.
  3. If defective, replace it with a new catalytic converter, ensuring proper alignment and fit.
  4. Reinstall the exhaust pipe and ensure all bolts are torqued to manufacturer specifications.
• Tools Required: Socket set, torque wrench, and exhaust gaskets.