Where is the fuel pressure regulator on 1999 3.8 camaro?

On a 1999 Camaro with the 3.8L engine, the fuel pressure regulator is integrated into the fuel rail. It's not a separate, easily identifiable component like on some other vehicles. You'll find it on the fuel rail itself, usually near the end opposite the fuel filter. You'll likely need to remove the upper intake manifold to access it properly.