Can I weld this directly into my exhaust system?

Yes. Mild steel is designed for welding. Clean the joint area with a wire brush before laying down beads. You can also clamp it using the flared ends if you prefer a non-permanent connection.

Do I need to seal or coat this before installing?

Not required, but recommended. Bare mild steel will rust over time when exposed to moisture and exhaust condensation. A high-temp exhaust coating or ceramic wrap extends the life of the pipe.

Will this fit my current exhaust clamps?

The 2.15" flared end is sized for standard exhaust clamps in that range. Verify your existing clamp diameter before ordering to confirm fitment.