how to fix P0420 code in Ford Explorer Sixth Generation (2020-present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Repair Exhaust Leaks

• Sub-steps:
  • Use a flashlight to visually inspect the exhaust system for cracks or holes.
  • If leaks are found, use exhaust sealant or replace the affected pipe or gasket.
• Tools Required: Wrench set, exhaust sealant
• Safety Warnings: Allow the exhaust system to cool before inspection to prevent burns.

3. Test and Replace Oxygen Sensors (if faulty)

• Sub-steps:
  • Use a multimeter to check the voltage output of the upstream sensor; it should fluctuate between 0.1V and 0.9V.
  • If the readings are out of this range, disconnect the sensor and replace it.
  • Repeat the same test for the downstream sensor; if faulty, replace it as well.
• Tools Required: Multimeter, socket set
• Safety Warnings: Disconnect the battery before working on electrical components.

4. Replace Catalytic Converter (if necessary)

• Sub-steps:
  • Remove any brackets or heat shields securing the catalytic converter.
  • Use a wrench to unbolt the catalytic converter from the exhaust system.
  • Install the new catalytic converter and secure it with bolts, ensuring to torque them to the manufacturer's specifications.
• Tools Required: Socket set, torque wrench
• Safety Warnings: Use protective gloves and eyewear when handling exhaust components.