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

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to ensure safety.
• Allow the vehicle to cool down before starting work.

2. Inspect and Replace Oxygen Sensors

1. Remove the upstream oxygen sensor:
   • Use an oxygen sensor socket or wrench.
   • Disconnect the electrical connector.
2. Install the new upstream oxygen sensor:
   • Thread it into the exhaust manifold and tighten to manufacturer specifications (usually 30-40 lb-ft).
   • Reconnect the electrical connector.
3. Remove the downstream oxygen sensor:
   • Follow the same procedure as above.
4. Install the new downstream oxygen sensor:
   • Torque to specifications.
   • Reconnect the electrical connector.

3. Inspect and Replace Catalytic Converter (if necessary)

1. Remove the old catalytic converter:
   • Disconnect the exhaust pipes using a socket set and wrench.
   • Unbolt any brackets or hangers holding the converter in place.
2. Inspect the exhaust system:
   • Make sure there are no leaks or blockages.
3. Install the new catalytic converter:
   • Align it with the exhaust pipes and secure it with bolts and brackets.
   • Apply exhaust sealant if necessary to ensure a proper seal.

4. Reset the Engine Control Module (ECM)

1. Reconnect the battery:
   • Reattach the negative terminal.
2. Use an OBD-II scanner:
   • Clear the P0420 code from the ECM.
3. Start the engine:
   • Let it idle for a few minutes to ensure proper operation.