how to fix P0420 code on my Honda Pilot YF4 (2023-Present)

Solution

1. Preparation

• Gather tools and safety equipment.
• Disconnect the battery to ensure safety while working on the vehicle.
• Tools Required: OBD-II scanner, multimeter, socket set, jack and jack stands.

2. Inspect and Replace Oxygen Sensors

• 2.1 Remove the upstream oxygen sensor:

  • Use a socket wrench to unscrew the sensor from the exhaust manifold.
  • Disconnect the electrical connector.

• 2.2 Install the new upstream oxygen sensor:

  • Apply anti-seize compound to the threads of the new sensor.
  • Screw it into the manifold and reconnect the electrical connector.

• 2.3 Repeat for the downstream oxygen sensor if found faulty:

  • Remove and replace using similar steps as the upstream sensor.

3. Check and Replace Catalytic Converter (if necessary)

• 3.1 Remove the catalytic converter:

  • Support the vehicle with jack stands.
  • Use a socket set to unbolt the catalytic converter from the exhaust pipes.

• 3.2 Inspect the old catalytic converter:

  • Look for signs of clogging or physical damage.

• 3.3 Install the new catalytic converter:

  • Position the new converter in place and secure it with bolts.
  • Ensure proper torque specifications are followed (typically 25-30 ft-lbs).

4. Reconnect Battery and Clear Codes

• 4.1 Reconnect the battery terminals.
• 4.2 Use the OBD-II scanner to clear the P0420 code from the vehicle’s computer.