When i install my Invidia 70mm Test Pipe onto the Stock Header and Greddy SE Dual Exhaust it blows somewhere, it must best be the donut gasket from the header to the testpipe, can it be that the testpipe is too big and i need a different gasket? Anyone who had this issue as well or anyone who knows which gasket is right? thanks!

 

I have the same setup except I have the se single and I have no leaks using he oem donut. I did have to change the gasket between the test pipe and exhaust with one from berk.

 

I'm running the same test pipe set up 70mm with factory header. It was leaking until I replaced the donut gasket and springs