The engine air filter element for the Duratec 35 3.5L V6 engine in a 1st generation (2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018 and 2019) Ford Flex should be cleaned at every oil change and replaced every 30,000 miles. Check out my DIY tutorial for changing the filter (with the compatible replacement part numbers) by clicking on the text link or thumbnail image below.
2009-2019 Ford Flex Engine Air Filter Replacement Guide
