how to fix P0420 code on Honda CR-V Fifth Generation (2017-2022)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal.
• Ensure the vehicle is on a level surface and secure it with wheel chocks.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Remove the upstream oxygen sensor:
  1. Locate the sensor before the catalytic converter.
  2. Use the O2 sensor socket to unscrew the sensor.
  3. Install the new sensor and torque it to manufacturer specifications (usually around 30 ft-lbs).
• Repeat for the downstream oxygen sensor located after the catalytic converter.

3. Inspect and Replace the Catalytic Converter

• Tools Required: Socket set, torque wrench, cutting tool (if necessary).
• Remove any components obstructing access to the catalytic converter.
• Disconnect the exhaust pipes:
  1. Unbolt the flanges connecting the converter to the exhaust pipe.
  2. Carefully lower the catalytic converter.
• Install the new catalytic converter:
  1. Position the new converter and align it with existing exhaust pipes.
  2. Torque bolts to manufacturer specifications (typically around 25 ft-lbs).
• Reattach any removed components carefully.

4. Reconnect Battery and Clear Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.
• Verify the vehicle runs properly without any warning lights.