My '96 SE has a flex pipe similar to the one you have in the picture. That part is original to the car and is standard production V6 fare. The assembly you have is definitely aftermarket, it appears to be an SHO shop version, but the heat shielding looks a bit different, it kind of looks like a BAT.

'96 SE 2.5 V6 ATX, Willow Frost Metallic 10-hole '84 Mustang 15x7 wheels w/ Dunlop 225/50-15's CSVT air intake components with K&N cone filter Optimized TB Gutted Pre-cats w/MIL eliminators