It's an easy repair.

Be sure to get two new gaskets -- one for the pipe-to-manifold, and one for the cat flange. In this case, original Volvo metal-clad gaskets are advised.

The one problem you should expect is that the three bolts securing the pipe flange to the mating flange on the catalytic converter will be rusted solid, and the bolt heads will be so rusted that a wrench won't bite. If you don't have an acetylene torch torch to help, then simply cut through the bolts. If your flange is the threaded type, then drill through the rusted-in remaining portions of the bolts to create clearance holes for new bolts. Then secure the new pipes with new bolts and nuts.
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Don Foster (near Cape Cod, MA)