I may have given the wrong advice. I was under the understanding you were removing the Exhaust manifold from the engine, not the Turbine outlet pipe. Your request stated Exhaust. From past experience it is the studs in the Cyl heads that always break and give grief. Best to check the Torque and stud size. Suggestion would be to swap the studs for Stainless types and never have the problem again. Removing the Turbo and removing the studs should not that big a deal.

 

Yes makes sense now

 

Back form the dead. Aluminum in contact with iron, main element in steel, will be sacrificial to the iron. Aluminum by itself will form an aluminum oxide on the surface. That oxide is pretty stable.

 

I fitted stainless steel studs+nuts . Got a $36 kit on Fleabay. You need to be able to measure stud threads accurately to make sure you get the correct kit.Similar to this:
http://www.ebay.com/itm/10-Piece-M8-...aeb1c2&vxp=mtr