Cracked Manifold/Downpipe?

[Jesse16v]

Since i got my car i have had this horrible rasping noise coming from the engine but i cant actually see where its coming from itself but it sounds like theres a leak somewhere on the manifold or downpipe, the car runs quite rich.

You can't really hear it until you accellerate over 2k , ive had the car for about 2 months now and its getting worse, could this be a my manifold or downpipe?

Has anyone else experienced this in the past?

[stan]

if its a williams manifold, they are prone to cracking on the inside at the joint for the 4 runners.
If its a valver manifold, check the main gasket to the downpipe and the gasket to the head.

[Jesse16v]

Sorry its a Valver manifold i have, is this easy to do? what do i have to do?