how to fix the P0420 code on my Honda Pilot YF3 (2016-2022)

Solution

1. Preparation

• Gather tools and ensure the vehicle is parked on a flat surface.
• Disconnect the battery to prevent electrical issues.
• Allow the engine to cool before working on the exhaust system.

2. Inspect and Repair Exhaust Components

• Inspect exhaust system:
  • Check for any cracks or holes in the exhaust pipes and catalytic converter.
  • Tighten any loose connections or replace damaged components as necessary.
• Repair or replace affected components:
  • If leaks are found, replace affected sections of the exhaust or the entire catalytic converter if damaged.

3. Replace Oxygen Sensors (if necessary)

• Remove the old sensors:
  • Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  • Use an oxygen sensor socket to unscrew and remove the sensors.
• Install new sensors:
  • Apply anti-seize compound to the threads of the new oxygen sensors.
  • Install the new sensors into their respective locations and torque them to the manufacturer’s specifications (typically around 30-40 lb-ft).

4. Reconnect Battery and Clear Codes

• Reconnect the battery terminals securely.
• Use the OBD-II scanner to clear the P0420 code from the system.

5. Test Drive

• Take the vehicle for a test drive to allow the engine control module to re-evaluate the catalytic converter efficiency.