i work in a nissan workshop and have seen many failure like this, also happened to my 2008 crd 3.0L
egr pipe can crack need the manifold, just replace the pipe with new gaskets
manifold can warp and snap studs, most common it the 2 in the front. best to fit a new manifold rather than machine them. also use new studs, nuts and gaskets.
ive seen some have a crack in the turbo as well so check that well.