2001 Mazda Millenia manifold vacuum line

Used a product Sea Foam to clear carbon. Requires you to pour through direct manifold vacuum line that will feed all cylinders. Just bought a 2001 Mazda Millenia and cant figure out appropriate vacuum line to use. Cant find a schematic anywhere.
Like the simplicity and cost of Chilton guides, cant find one for this vehicle.
Thanks for any assist,
Dennis