i just finished installing my ultimate racing 2.5 hi flow cat that i bought from a member on this site. i have a stock downpipe and a hks hi-power exhaust and the U-R cat is leaking at the gaskets. i need some advice on how to fix the problem. they are new gaskets, can i buy another set and double them up? or do i buy a test pipe? if a test pipe is suggested what will bolt up to a stock downpipe and hks hi power exhaust?

 

Try some Ultra Copper Gasket maker , it's kind of like silicone glue but better on exhaust system. You can pick it up at any auto parts store. Put it on both sides of the gasket.

 

i bought some of the gasket maker you suggested and will try it tomarrow. but now i am thinking of just going with a 3 inch test pipe from ultimate racing. there website says that it is a direct replacement but can anyone tell me it will bolt up to the stock downpipe?

 

bought the permatex as suggested, woke up early and applied it on both sides of my gaskets. i let it cure for 2 hours then started it up and checked for leaks, and none were to be found . i am going to let it cure for 24 hours per the directions. thanks for the help
here is a pic of suggested permatex product