I installed the draft tube mod. and ran the hose to the back. It`s been on for about 3-4 months. Just tonight I get out to hook up the trailer and notice a heavy cooked oil smell. I get a flashlight and shine it at the tube exit and can see a mist pooring out. Not enough to drip, but a heavy stream of cloudy vapor. I never noticed it before. Did it do that all the time, or did something get stuck in the "black box" that sits on the valve cover?