how to fix Honda CR-V Sixth Generation (2023-present) P0420 code

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect Exhaust System

• Tools Required: Socket set, flashlight
• Remove any undercarriage covers if necessary.
• Visually inspect the exhaust pipes, joints, and catalytic converter for cracks or holes.
• Repair or replace any damaged components as needed.

3. Test Oxygen Sensors

• Tools Required: Multimeter
• Locate the upstream and downstream oxygen sensors.
• Disconnect the connectors and set the multimeter to measure voltage.
• Start the engine and monitor the voltage output; the upstream sensor should fluctuate between 0.1V and 0.9V rapidly, while the downstream should be relatively stable.
• Replace any faulty sensors based on the readings.

4. Inspect and Replace Catalytic Converter (if needed)

• Tools Required: Socket set, torque wrench, gaskets
• Remove the exhaust pipe connected to the catalytic converter.
• Unbolt the catalytic converter from the exhaust manifold and remove it.
• Inspect the old catalytic converter for damage or clogging.
• Install the new catalytic converter, ensuring proper alignment and torque specifications (usually around 25-30 lb-ft).
• Replace any gaskets or hardware as necessary.

5. Reconnect Battery and Clear Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.