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

Solution

1. Preparation

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

2. Inspect and Replace Oxygen Sensors

• Sub-steps:
  1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
  2. Unplug the electrical connectors from both sensors.
  3. Use an O2 sensor socket to remove the sensors from the exhaust pipe.
  4. Install new oxygen sensors and torque them to manufacturer's specifications (typically around 30 lb-ft).
  5. Reconnect the electrical connectors.

3. Check and Replace the Catalytic Converter

• Sub-steps:
  1. Inspect the catalytic converter for physical damage or blockage.
  2. If damaged, unbolt the catalytic converter from the exhaust system.
  3. Install a new catalytic converter, ensuring all gaskets and seals are replaced.
  4. Torque the bolts to the manufacturer's specifications (typically around 40 lb-ft).
  5. Reconnect any exhaust hangers or brackets.

4. Clear the Codes

• Sub-steps:
  1. Reconnect the battery.
  2. Use an OBD-II scanner to clear the P0420 code from the ECM.
  3. Start the engine and allow it to reach operating temperature.