Does this bolt directly to the factory cat, or do I need an adapter?

This is a catback system, so it connects at the catalytic converter outlet and bolts there. Confirm your cat outlet diameter matches the inlet on this system before ordering.

Do I need to weld this on, or does it use clamps and hangers?

Mounting method not specified in product data. Before installation, verify whether your vehicle uses factory rubber hangers or brackets that accept bolt-on clamps — test-fit the system to determine what fasteners you'll need.

Will stainless steel require any prep or coating before I install it?

Stainless steel arrives ready to bolt on — no painting or chemical prep needed. You can install it as-is.