Hi guys, Coming off a short trip, I heard alot of blowby out of my ehaust manifold. Turns out there's a broken stud and it's leaking exhaust bad. I was told the manifold, head needs to be taken off and tested to see if the blow by damaged the manifold by leaking, would blow by damage the manifold?

Also, what is the usual repair bill for a manifold stud replace/gasket replace??? I'm in Louisiana.

She's an 1.8 A4 Turbo, 5-speed, and ultra sweet!

Thanks!!!