In the very front of every 95 940 b230f engine there is a rubber hose coming from the air filter intake box that crosses over to what appears to be a small, vacuum operated diaphram valve, locatedn just in front (and slightly to the right) of the valve cover. The valve outlet diverges into 2 hoses that connect to stainless pipes.

Can anyone tell me exactly what this valve/hose is and what it does? Most importantly, I took it off to inspect the integrity of the rubber fitting which has begun cracking due to heat and age. There is an arrow on the valve, but I failed to note if the arrow pointed toward (or away) from the air intake box? After installing it pointing toward the box, car seems to run ok, but the 'check engine' light has come on. It resets by battery disconnect, but returns after 10 mins driving.

thanks in advance.