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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to avoid electrical issues.
• Allow the engine to cool down before starting any work.

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
   • Tools: O2 sensor socket or wrench.
2. Remove the upstream O2 sensor.
   • Use the O2 sensor socket to unscrew the sensor.
3. Install the new upstream O2 sensor.
   • Torque to manufacturer specifications (typically around 30 lb-ft).
4. Repeat for the downstream O2 sensor if necessary.

3. Inspect and Replace the Catalytic Converter

1. Remove the exhaust system components connected to the catalytic converter.
   • Tools: Socket set, ratchet, and possibly a torch for stubborn bolts.
2. Detach the catalytic converter from the exhaust manifold and exhaust pipe.
   • Ensure to support the exhaust system to prevent strain.
3. Inspect the old catalytic converter for internal damage or blockage.
4. Install the new catalytic converter.
   • Ensure proper fitment and alignment.
   • Torque bolts to manufacturer specifications (usually between 25-30 lb-ft).
5. Reattach any exhaust components previously removed.

4. Reconnect Battery and Clear Codes

1. Reconnect the vehicle's battery.
2. Use the OBD-II scanner to clear the P0420 code.
3. Start the engine and allow it to reach operating temperature.