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

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Oxygen Sensors

• Tools Required: O2 sensor socket, ratchet, torque wrench.
• Steps:
  1. Locate the upstream and downstream oxygen sensors.
  2. Use the O2 sensor socket to remove the upstream sensor.
  3. Inspect the sensor for contamination or damage.
  4. Install the new upstream oxygen sensor and tighten to manufacturer specifications (typically around 30 ft-lbs).
  5. Repeat for the downstream oxygen sensor.

3. Inspect and Replace Catalytic Converter

• Tools Required: Socket set, cutting tool (if necessary), exhaust sealant, torque wrench.
• Steps:
  1. Locate the catalytic converter in the exhaust system.
  2. If needed, cut the exhaust pipes to remove the catalytic converter. Ensure you have proper sealing surfaces.
  3. Install the new catalytic converter, ensuring the inlet and outlet are correctly oriented.
  4. Secure with bolts and gaskets, and tighten to manufacturer specifications (typically around 40 ft-lbs).
  5. Use exhaust sealant on connections if required.

4. Reconnect Battery and Clear Codes

• Reconnect the negative battery terminal.
• Use an OBD-II scanner to clear the P0420 code from the system.