a kits that claims to Upgrade stock Subaru TD05H-16G to 18G version

[Longshot]

Get rid of the ebay uppipe and put your stocker back on. Did you reuse the gaskets? The flex section tends to leak in those, and if you used their gaskets chances are you'll get a leak there also. Your 07 stock uppipe is plenty sufficient.

[cobra121990]

i changed the up-pipe and it works fine. I used the stock gaskets and bought new gaskets not the ones that they came with for the rest of the exhaust and i wasn't planning on surpassing the sti with just that i was just asking all your opinion on the part. Apparently its a no. thankyou