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

Solution

1. Preparation

• Gather the necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the exhaust system to cool before starting work.

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream (pre-catalytic) and downstream (post-catalytic) oxygen sensors.
2. Use a socket wrench to remove the oxygen sensors from their respective locations.
3. Inspect the sensors for damage or contamination.
4. If faulty, install new oxygen sensors, ensuring they are torqued to manufacturer specifications (usually around 30 Nm).
5. Reconnect the electrical connectors securely.

3. Inspect and Replace Catalytic Converter

1. Remove the exhaust system components leading to the catalytic converter (if necessary) using a socket set.
2. Unbolt the catalytic converter from the exhaust manifold and the exhaust pipe.
3. Inspect the old catalytic converter for damage or blockage and replace it if necessary.
4. Install the new catalytic converter, ensuring all bolts are tightened to the manufacturer's torque specifications.
5. Reassemble any removed exhaust components securely.

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.