My drain valve is colsed and hoses all the way on! The earlier thread was about this same issue and I thought the drain was open so I thought I closed it and the hissing went away. Problem was that now it was really open. I discovered it when I removed the can and blew into the input and felt air come out of the drain. So, I re-installed it, closed the drain and HISS! If this ends up to be normal I'm pulling it out and returning it! It is quite loud and can be heard with the hood closed and idling and is very annoying. It really irritates me when you install a performance mod and it makes noise, or squeeks, or hisses, or causes another problem!
