ARM Motorsports MK5 GTI Catted Downpipe boosts horsepower up to +20whp and +30wtq. It also improves the turbo spool on your 2.0T, allowing your GTI to reach boost sooner at lower rpm.
WHY DO YOU WANT A CATTED  DOWNPIPE?
Great question ! There are several reasons why you would want a downpipe with a cat for your GTI over a downpipe system without a cat.
Passing Emissions: One of the biggest benefits of a catted downpipe is that it increases your chances of passing emissions. * The catalytic converter in the catted ARM GTI downpipe is significantly less restrictive than the OEM catalytic converter, allowing it to increase the horsepower of your 2.0T while working to burn unheard exhaust not with the environment and the EPA.
NO HARMFUL SMELL: Well, at least from your exhaust. The catted downpipe destroys most of the elements in the exhaust typically associated with catless downpipes that produce heavy exhaust fumes. If you've owned a vehicle with a catalystless exhaust, you're probably familiar with the smell associated with a catalystless downpipe. The catted ARM GTI downpipe eliminates the smell of many exhaust fumes above what you would experience with the OEM downpipe.
EXHAUST SOUND : Many enthusiasts prefer the sound of a catted downpipe to the standard catless downpipe. Having the catalytic converter in your GTI's downpipe reduces some of the high-pitch rasp typically associated with catless systems. It acts almost like a resonator in the way it affects the acoustics of the exhaust note.

CONSTRUCTION
The ARM MK5 GTI downpipe features a 3" all stainless steel construction with smooth elbows for improved exhaust flow. The top of the downpipe has a CNC machined flange that mates to the turbo and includes a flex joint to relieve stress and make installation easier. The downpipe section at the catback is where the converter is placed 200 cell sport catalytic. The catted ARM downpipe kit is designed to fit both CBFA and CCTA applications, so you can be sure that whatever version of the 2.0T you have the ARM downpipe will accommodate your GTI.
BOLTS UP TO STOCK OR AFTERMARKET CATBACK EXHAUST
The catted ARM MK5 GTI downpipe will fit the existing OEM catback exhaust or any aftermarket exhaust that connects to the OEM downpipe. The ARM downpipe kit includes a 3" to 2.25" reducer to allow it to fit perfectly with the stock exhaust system. Or choose to hook up to a 3" aftermarket exhaust system for a full 3" turbo-back setup.