how to fix P0420 code in Ford Explorer Fifth Generation (2011-2019)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative battery terminal to ensure safety.
• Allow the engine to cool before working on the exhaust system.

2. Inspect and Replace Oxygen Sensors

1. Locate the oxygen sensors: Identify the upstream and downstream oxygen sensors on the exhaust system.
2. Remove the sensors: Use an oxygen sensor socket to carefully unscrew and remove the sensors from the exhaust system.
3. Inspect the sensors: Check for any signs of wear or damage on the sensors. If they appear faulty, proceed to replace them.
4. Install new sensors: Apply anti-seize compound to the threads of the new sensors and install them securely, ensuring they are tightened to manufacturer specifications (typically around 30-40 ft-lbs).
5. Reconnect the electrical connectors: Ensure the connectors are firmly attached and secure.

3. Inspect and Replace the Catalytic Converter

1. Check for damage: Examine the catalytic converter for any visible damage or signs of clogging.
2. Remove the old catalytic converter: If replacement is necessary, unbolt the catalytic converter from the exhaust system using a socket set, ensuring to support it properly to avoid damage.
3. Install the new catalytic converter: Position the new converter in place, securing it with new bolts if necessary. Torque the bolts to the manufacturer's specifications (usually around 25-35 ft-lbs).
4. Reconnect exhaust system: Ensure that all connections are tight and leak-free.

4. Clear Error Codes and Test Drive

1. Reconnect the battery: Reattach the negative battery terminal.
2. Clear the error codes: Use an OBD-II scanner to clear the P0420 code from the system.
3. Test drive: Drive the vehicle for a minimum of 20 minutes to ensure the system monitors the sensors and checks for any reoccurring codes.