my Honda Pilot YF4 (2023-Present) has a P0420 code, how do I fix it?

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, multimeter, jack and jack stands, safety goggles, gloves.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the battery to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Step 1: Remove the upstream oxygen sensor.

  • Use the appropriate socket to unscrew the sensor from its mounting point.

• Step 2: Install a new upstream oxygen sensor.

  • Apply anti-seize compound to the threads of the new sensor and screw it into place. Torque it to the manufacturer's specification (usually around 30 lb-ft).

• Step 3: Repeat for the downstream oxygen sensor if necessary.

  • Follow the same procedure as above for removal and installation.

3. Inspect and Replace Catalytic Converter (if necessary)

• Step 1: Remove the exhaust components leading to the catalytic converter.

  • Use a socket set to unbolt the exhaust pipe from the catalytic converter.

• Step 2: Remove the catalytic converter from its mounting brackets.

  • Ensure to disconnect any heat shields or additional brackets that may be in the way.

• Step 3: Install the new catalytic converter.

  • Position the new converter and secure it with the original bolts. Torque to manufacturer specifications (check service manual for exact values).

• Step 4: Reattach the exhaust system components.

  • Ensure all connections are tight and secure.

4. Reset Engine Control Unit (ECU)

• Step 1: Reconnect the battery.
• Step 2: Use the OBD-II scanner to clear the P0420 code from the ECU.