how to fix P0420 code in Honda Pilot YF3 (2016-2022)

Solution

1. Preparation

• Gather tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

1. Locate the Oxygen Sensors: Identify the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
2. Remove the Oxygen Sensors:
   • Use an oxygen sensor socket and ratchet to unscrew the sensors.
   • Disconnect the electrical connectors.
3. Install New Oxygen Sensors:
   • Apply anti-seize compound to the threads of the new sensors.
   • Install the sensors hand-tight, then use the socket to tighten to the manufacturer's specification (usually around 30 ft-lbs).
   • Reconnect the electrical connectors.

3. Inspect and Replace Catalytic Converter (if necessary)

1. Examine the Catalytic Converter: Look for signs of damage or excessive rust.
2. Remove the Catalytic Converter:
   • Unbolt the flanges connecting the catalytic converter to the exhaust system using a socket set.
   • If necessary, cut the catalytic converter off using a reciprocating saw.
3. Install New Catalytic Converter:
   • Position the new catalytic converter in place.
   • Bolt it to the exhaust system and ensure all connections are secure.
   • Torque the bolts to the specified value (typically around 25-35 ft-lbs).

4. Reset the Engine Control Module (ECM)

1. Reconnect the Battery: Reconnect the negative battery terminal.
2. Clear the Codes: Use the OBD-II scanner to erase the P0420 code from the vehicle's memory.