how to fix Honda Accord 9th Generation (2013-2017) P0420 code

Solution

1. Preparation

• Gather all necessary 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. Remove the Downstream Oxygen Sensor

   • Locate the downstream oxygen sensor (usually near the catalytic converter).
   • Use an O2 sensor socket to carefully unscrew the sensor.
   • Disconnect the sensor’s electrical connector.

2. Install New Downstream Oxygen Sensor

   • Connect the new sensor to the electrical connector.
   • Screw the sensor into the exhaust system using the O2 sensor socket.
   • Torque to manufacturer specifications (typically around 30 ft-lbs).

3. Inspect and Replace Catalytic Converter

1. Remove the Catalytic Converter

   • Locate the catalytic converter.
   • Use a socket set to remove the bolts securing the converter to the exhaust pipes.
   • Carefully lower and remove the old catalytic converter.

2. Install New Catalytic Converter

   • Position the new catalytic converter in place.
   • Secure it using new bolts and gaskets where necessary.
   • Torque bolts to manufacturer specifications (typically around 33 ft-lbs).

4. Reconnect Battery and Clear Codes

• Reconnect the battery terminal.
• Use the OBD-II scanner to clear the P0420 code from the ECU.