my Honda Pilot YF3 (2016-2022) keeps throwing P0420 code what does it mean

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, socket set, torque wrench.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery before starting work on electrical components.

2. Inspect and Replace Oxygen Sensors

1. Locate the Oxygen Sensors:

   • Identify the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.

2. Remove the Oxygen Sensors:

   • Use a socket or wrench to carefully unscrew the sensors from their locations.
   • Apply penetrating oil if they are difficult to remove.

3. Install New Oxygen Sensors:

   • Apply anti-seize compound to the threads of the new sensors.
   • Install the new sensors, torque to manufacturer specifications (typically 30-50 lb-ft).

3. Inspect and Replace Catalytic Converter (if necessary)

1. Remove the Exhaust System Components:

   • Unbolt the exhaust pipe from the catalytic converter using a socket set.
   • Support the exhaust system with a jack or stands to prevent strain.

2. Remove the Catalytic Converter:

   • Unbolt the catalytic converter from the exhaust manifold and exhaust pipe.
   • Remove any heat shields or brackets as necessary.

3. Install New Catalytic Converter:

   • Position the new catalytic converter and secure it to the exhaust manifold and pipe.
   • Torque the bolts to specifications (check service manual for specific values).

4. Reconnect Battery and Clear Codes

• Reconnect the battery terminals.
• Use the OBD-II scanner to clear any trouble codes from the system.