Quick view Stainless Works Stainless Works 15-18 F-150 3.5L Downpipe 3in High-Flow Cats Y-Pipe Factory Connection - FT16ECODPCAT Compare $1,571.00 $1,492.99 2015-16 F150 3.5L Ecoboost Downpipe. Stainless steel 3" downpipe with catted lead pipes. Includes Y-pipe to fit to flanged factory connection point.This Part Fits:YearMakeModelSubmodel2015-2018FordF-150King... Add to Cart Add to Cart