my Honda CR-V Fifth Generation (2017-2022) has a check engine light and code P0420, what to do?

Solution

1. Preparation

• Gather tools and parts needed for repair.
• Park the vehicle on a level surface and set the parking brake.
• Disconnect the battery negative terminal to ensure safety during repairs.

2. Inspect Catalytic Converter

• Tools Required: Jack and jack stands, socket set.
• Raise the vehicle using a jack and secure it with jack stands.
• Visually inspect the catalytic converter for cracks, dents, or damage.
• Tap the converter lightly; if you hear rattling, the internal substrate may be damaged.

3. Replace Oxygen Sensors (if needed)

• Tools Required: O2 sensor socket, torque wrench.
• If the oxygen sensors are faulty, unscrew them using the O2 sensor socket.
• Install new sensors in the same location, using the torque specifications provided by the manufacturer (typically 30 lb-ft for O2 sensors).
• Reconnect the electrical connectors securely.

4. Replace Catalytic Converter (if necessary)

• Tools Required: Cutting tool (if needed), socket set, exhaust sealant, torque wrench.
• If the catalytic converter is damaged, remove it by unbolting it from the exhaust system (may require cutting if welded).
• Install the new catalytic converter using exhaust sealant on the flanges to prevent leaks.
• Torque the bolts to the manufacturer's specifications (usually around 40 lb-ft).

5. Reconnect Battery and Clear Codes

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