[Old Guy with 87 GT]

if your car is equiped with a mass air sencer then ,no it doesn't get a vac line attached

89 and up mustangs have a mass air ecu it only uses that sencer to read atmospheric pressure

86-88 mustangs have a speed density ecu ,there the ones that need the vac line attached to that senser.....speed density needs the sencer for reading engine load as well as atmospheric pressure

......the sencer on both speed density and mass air are identacal sencors except for the little white fitting to prevent a vac line being attached for the mass air cars........somtimes peaple miss match and use the ones with out the white fitting cause there basicly the same sencer ,just used for different purposes