Will this need to be welded in, or is it a straight bolt-on?

Bolt-on to your factory catalytic converter—no welding or cutting needed. Fasteners and mounting method are designed for direct installation without modification to your existing exhaust system.

Do the burnt tips come pre-finished, or do I need to polish or treat them?

The tips arrive with burnt finish already applied. They're ready to install as-is—no additional polishing or prep required before bolting on.

What kind of sound increase should I expect?

You'll hear a noticeable mid-range to high-RPM tone increase over stock. Exact character depends on your driving style and any other modifications, but this catback is tuned for audible response without drone at cruise.