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

Solution

1. Preparation

• Gather tools and parts necessary for the repair.
• Disconnect the vehicle's battery to prevent electrical shorts.
• Safety goggles and gloves should be worn throughout the process.

2. Inspect and Replace Oxygen Sensors

1. Locate the oxygen sensors: Identify the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
2. Remove the upstream sensor:
   • Use an O2 sensor socket and ratchet to unscrew the sensor.
   • Disconnect the electrical connector.
3. Install the new upstream sensor:
   • Apply anti-seize compound to the threads.
   • Screw in the new sensor and connect the electrical harness.
4. Repeat for the downstream sensor: Follow the same steps to replace the downstream O2 sensor if it was found to be defective.

3. Inspect and Replace the Catalytic Converter

1. Check for blockages or damage: Inspect the catalytic converter for any signs of physical damage or clogging.
2. Remove the catalytic converter:
   • Loosen and remove the bolts or clamps securing the catalytic converter to the exhaust system using a socket set.
   • Carefully take out the catalytic converter from the exhaust system.
3. Install the new catalytic converter:
   • Position the new catalytic converter and secure it with bolts or clamps.
   • Ensure all connections are tight and there are no leaks.

4. Reset the Engine Control Module (ECM)

1. Reconnect the battery: After completing the repairs, reconnect the battery terminals.
2. Use an OBD-II scanner to clear the P0420 trouble code from the ECM.