Constructed from tig-welded T-321 stainless steel with 1/2" thick flanges, the Perrin uppipe for your 02-07 WRX & STI is designed to handle the extreme heat of your Subaru's turbocharged engine without warping or cracking. Bolt this product up to your turbo and you will experience quicker spool, more power and snappier low end throttle response. The Perrin uppipe includes detailed instructions and new studs to make installation of this part as easy as possible. The Perrin uppipe does delete the factory EGT sensor on 02-05 WRX models, so engine management or the 'resistor mod' will be necessary to eliminate the inevitable check engine light that you encounter. Please call for more information. Replacement gaskets are recommended but not included.