Ford Explorer Sixth Generation (2020-present) check engine light with P0420 code what does it mean

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Raise the vehicle using a jack and support it with jack stands for safe access.

2. Inspect and Replace Oxygen Sensors

1. Locate the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
2. Using a socket or wrench, carefully remove the oxygen sensors from their respective positions.
3. Inspect the sensor connectors for corrosion or damage.
4. Install new oxygen sensors and torque them to manufacturer specifications (usually around 30 lb-ft).
5. Reconnect the electrical connectors securely.

3. Inspect and Replace Catalytic Converter (if necessary)

1. If the temperature test indicates a failing catalytic converter (inlet temperature significantly lower than outlet), proceed to replace it.
2. Remove any heat shields or components obstructing access to the catalytic converter.
3. Unbolt the catalytic converter from the exhaust system using a socket set.
4. Install the new catalytic converter, ensuring proper alignment and sealing.
5. Torque the bolts to the manufacturer’s specifications.

4. Clear Codes and Test

1. Reconnect the negative battery terminal.
2. Use the OBD-II scanner to clear any stored codes.
3. Start the engine and allow it to reach operating temperature.
4. Test drive the vehicle for a short distance to check if the check engine light re-illuminates.