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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal.
• Allow the engine to cool down before working on exhaust components.

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
2. Use an O2 sensor socket to remove the upstream sensor and inspect its condition.
   • Tools Required: O2 sensor socket
3. If the sensor shows signs of wear or damage, replace it with a new one.
4. Repeat the process for the downstream oxygen sensor, if necessary.

3. Inspect and Replace the Catalytic Converter

1. Visually inspect the catalytic converter for any signs of physical damage or clogging.
2. If it is clogged or damaged, remove the catalytic converter by unbolting it from the exhaust manifold and the exhaust pipe.
   • Tools Required: Socket set, torque wrench
3. Install the new catalytic converter, ensuring proper alignment and securing with bolts to manufacturer specifications.
4. Torque the bolts to the manufacturer's specifications (usually around 30-50 lb-ft, check service manual for exact values).

4. Reset the Engine Control Module (ECM)

1. Reconnect the negative battery terminal.
2. Use the OBD-II scanner to clear the P0420 code from the ECM.
3. Start the engine and allow it to reach operating temperature.