Ford Explorer CAT Sensor
Some 2014-2015 Ford Explorer vehicles equipped with a 3.5L or 3.7L Ti-VCT engine may exhibit an illuminated MIL with DTC P0138 (bank 1 CMS) and/or P0158 (bank 2 CMS) stored in the PCM memory.
Connect your scan tool and check for DTCs. Address any non-related DTCs before continuing. Replace the affected catalyst monitor sensor (CMS).
The sensors are available as follows:
Bank 1 CMS......BE5Z-9G444-B
Bank 2 CMS......BE5Z-9G444-A