The COBB Subaru J-Pipe for the 2015+ WRX is a direct replacement unit which features full CNC mandrel bent 304 stainless steel construction, a high quality metal spun catalytic converter, and an adapter for use with the factory catback. All of these features combine into an excellent replacement for the power robbing factory unit.
The COBB J-Pipe replaces what is traditionally referred to as the "downpipe" on previous Subaru vehicles. With the relocation of the turbocharger for the 2015+ WRX, the first section of exhaust no longer requires a downward turn but instead uses a sharp "j-turn" to route exhaust towards the back of the vehicle. During testing, we discovered when running a stock cat-back with an upgraded J-Pipe, there was a resonance issue when cruising at highway speeds. Thus, we have gone a step above and beyond to offer a resonated version to our customers that want to keep their stock cat-back. You can also use the resonated J-Pipe if you want to quiet down the turboback system.