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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety while working with electrical components.

2. Inspect Oxygen Sensors

• Locate the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
• Unplug the connectors from both sensors.
• Use a multimeter to test the voltage signal from the upstream sensor while the engine is running (should fluctuate between 0.1V to 0.9V).
• If the upstream sensor is faulty, replace it.

3. Replace Catalytic Converter (if necessary)

• Raise the vehicle using a jack and secure it with jack stands.
• Remove the heat shields if applicable to access the catalytic converter.
• Unbolt the catalytic converter from the exhaust system using a socket set.
• Carefully remove the old catalytic converter from the exhaust pipe.
• Install the new catalytic converter, ensuring proper alignment and fit.
• Torque the bolts to the manufacturer's specifications (typically around 30-40 ft-lbs, but verify specific torque values for your model).

4. Reconnect Oxygen Sensors

• Reconnect the upstream and downstream oxygen sensors to their respective connectors.
• Ensure the wiring harness is secure and free from damage.

5. Reconnect Battery and Perform Reset

• Reconnect the vehicle's battery.
• Use the OBD-II scanner to clear the P0420 code from the vehicle’s computer.
• Start the engine and allow it to reach normal operating temperature.