any advice on a method to track down the source of an exhaust leak. I have tried to listen for it, but no luck. I noticed that my A/C compressor is covered in soot. Not sure why i never realized before. I think it points to the lines leaking at the compressor and a leak in the exhaust nearby in either the manifold or downpipe.

Any suggestions on how to replace broken parts of the exhaust.Are there any aftermarket manifolds that are worth buying? or is used the best bet?

 

Leaking AC compressor usually creates a ring of oil/dirt slung out by rotating compressor clutch and pulley. May not be an indication of exhaust leak.

Exhaust leaks can be many places, but flex-joint is a prime candidate. Elevate on ramps or have inspected by a good muffler shop.

OEM manifold is usually well protected from corrosion by the external heat shield, however exhaust manifold gasket can leak. Also manifold to exhaust pipe connection may leak.

good luck