Mongoose Ford Fiesta Mk7 ST180 Downpipe/DecatMongoose are proud to release their new product for the Fiesta ST180 1. 6 Ecoboost. Our modular design initially looks complicated but it all has a reason 1, Mongoose designed this using 76mm Pipework and flexi section, this was then split into two parts to make it easier to ship and to install. 2, The flexi section comes as 2 different options, with either a 2. 5 flange or 3 flange on the end where it meets the rest of the cat back system. We wanted