WARNING: This page is about a different car, the 2013 Acura MDX, 2012 Acura MDX, 2011 Acura MDX, and 2010 Acura MDX. However, it is still accessible from the selected car via links, so may be relevant.
The FTP sensor converts fuel tank absolute pressure into an electrical input to the PCM.
Fig 1: Identifying Fuel Tank Pressure (FTP) Sensor Terminal And O-Ring