how do I resolve the P0420 code on my Honda CR-V Fifth Generation (2017-2022)

Solution

1. Preparation

• Ensure the vehicle is parked on a level surface and the engine is cool.
• Gather the necessary tools and replacement parts.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet and extension, torque wrench.
• Sub-steps:
  1. Disconnect the battery to prevent electrical shorts.
  2. Locate the upstream and downstream oxygen sensors (typically found before and after the catalytic converter).
  3. Use the O2 sensor socket to carefully unscrew the sensors from their locations.
  4. Install new oxygen sensors, tightening them to the manufacturer's specified torque (usually around 30 ft-lbs).
  5. Reconnect the electrical connectors for both sensors.

3. Inspect and Replace Catalytic Converter (if necessary)

• Tools Required: Socket set, torque wrench, exhaust hanger removal tool.
• Sub-steps:
  1. If the catalytic converter is damaged, mark the location of the exhaust flanges.
  2. Use the exhaust hanger removal tool to detach the exhaust system from its hangers.
  3. Remove the bolts securing the catalytic converter to the exhaust system and drop it carefully.
  4. Install the new catalytic converter, ensuring all gaskets are in place.
  5. Reattach the exhaust system, tightening bolts to the manufacturer’s specified torque (typically around 20-25 ft-lbs).

4. Reset the Check Engine Light

• Reconnect the battery and use the OBD-II scanner to clear the P0420 code.