yeah - the thing is i didnt test them before hand as they were ceramic coated and wrapped. I took the wrapping off when i re-did my downpipe, and notice it was pretty bad.
The exhaust shop tried to fix it as much as they could but they still leak bad.

Its actually a common problem - heaps of people with same issues over on iwsti and nasioc... happens to most slip joins if they dont carbon up properly.
Fix is either to weld... which i dont really wanna do.. or get some sort of tube clamps. Dunno which way im gonna go yet.