Yes they all came with the sound tube. I didn't remove mine but I did put an on/off valve in line so that I could try it both ways. Mostly left turned on. Wrong answer. Go to the back of the queue.
Yup, disconnect it and cap it off at your intake and (don't waste your time trying to remove the nut on the firewall).. just yank it out of the firewall and get a rubber plug from advanced auto and plug the hole in the firewall.