Need Help Identifying Hose
 

While changing air filters (1st time after purchase for me) on 92 500SL, I found a disconnected hollow hose behind and under passenger side air filter cover when removed. It is about 4 to 5 mm in diameter, translucent (teflon?) with a yellow stripe on it. When traced, it passes between fuel injection distributor and air intake horn and appears to be connected to and under a control valve (?) located adjacent to the fuel injection distributor. It does not appear to have a vacuum or liquid conveying function. Can anyone tell me what it is and to what it should be connected. This control valve (not sure of function or proper name) seems to have something to do with the HVAC system since it is connected with metal lines to fuel injection distributor and an air conditioner hose.