Starla cat back Here:
https://www.fcpeuro.com/products/volvo-exhaust-system-muffler-kit-240



iPd sells stainless off brand cat back systems.
https://www.ipdusa.com/Catalog/Index?CAT_ID=1034

Some will use OE Volvo clamps and hangers. 1991 240 US has the metal do'hnut! spin gasket at the header pipe out to catalytic converter inlet. The three studs from the cat may be feeble after 32 years. I've remove the cat, used a press or auto machine shop to press these studs out. The spline interface was then sharp on the plate on the cat. Used as large a diameter hardware for high heat and torque, And does well. Original cat!

Also, it is primarily critical the header pipe just before the outlet is supported by the bracket attached to two bell housing bolts. There is a plate in between shaped like an L. These rust as do the break away in an accident welds that secure the single piece of thick sheet steel with the steel embedded fastener, a hex nut usually, used to secure that L bracket to the header pipe end near the outlet. That L plate secures to the bracket in two places. M8 or M10 hardware (bolts, nuts, washers). A hard to access nook to be sure.

That bracket also connects the exhaust to DC earth / ground. In fancier cars, the exhaust system is connected to the body, and earthed, at exhaust system unions with an appropriate conductor / insulation connecting the exhaust in an electrical bond to the body. I've used braided copper alloy and steel ground straps meant for the under Volvo 240 environment. Up to the last union where the tailpipe connects to the rear muffler / resonator (if you have one). Your exhaust system may remain for a very long time, like decades, as has on my 240s.

Many other articles here for exhaust service. Maybe look at the exhaust page in the 700/900 FAQ? Not the same parts yet the same exhaust system.

\https://www.brickboard.com/FAQ/700-900/Exhaust.htm

Also, if not already, how are the exhaust manifold gaskets when you look at an edge. Rusty and flaky? The studs are a service item as these rust, can seize and snap. The newer studs from Volvo are beefier yet you can find premium hardware at McMaster-Carr, Fastenal, Fasteners, and maybe the higher priced Grainger outlets.

Use nickel anti-seize on studs and all fastening hardware.

May be able to find it cheaper elsewhere. A little cheaper.

Questions?
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