FINALLY you have an option for an extra thick Exhaust Manifold-to-Up Pipe Gasket. The most troublesome mating joint in the Subaru exhaust track is the manifold to up pipe connection. GrimmSpeed came up with a gasket that is more than twice as thick as the OEM gasket. With a whopping twelve layers, it is 2.5mm thick...a monster compared to the 1.2mm thick OEM gasket! 

Whether it is OEM Manifold > OEM Up Pipe, OEM Manifold > Aftermarket Up Pipe, Aftermarket Header > Aftermarket Up Pipe....they all have leaking issues at this connection. The GrimmSpeed 2x-thick gasket solves this problem. This is a premium multi-layer, extra-thick steel gasket with stainless steel fire-ring.

Fits all 2002-2014 Subaru WRX and STI, and all 2015 STI. Also fits 2005-2009 Legacy GT and Outback XT, and 2003-2013 Forester XT.