I was doing some maintenance on my 2006 Turbo S. Specifically the valve cover gaskets. The car only has 54,000 miles on it and both sets of gaskets were hard as rocks. Actually cracked when I tried removal. I don't think they're doing much anymore.
On the passenger side I found a line on top of the engine that was not connected. Specifically it comes off as a T from the little plastic line that connects the two valve covers. I temp repaired it with some fuel line in a couple clamps. Does anyone know what this line actually does?
On the driver's side I found that my Turbo actuator line was cut by the pulley above the tensioner and was open to air. This probably happened as a result of me replacing the water pump and drive belt two months ago. I replaced it and all is good.
A question I have, if the Turbo actuator line was open to air would it cause over boost or under boost? I'm trying to figure out if the actuator opens or closes the Turbo bypass.

A car seem to suffer from that low psi limp mode before I replaced the valve cover gaskets and found these two leaks.

 

From what I can see on the engine diagrams. There's a tube that takes either suction or pressure from the passenger side turbo. Runs it up to an electronic valve next to the throttlebody. The valve then sends either the vacuum or pressure to the turbo actuators on both sides. This is done to decrease the turbo pressure.
So if the line was broken or disconnected it should get over boost.
Still don't know what the valve cover vent tube connects to in the back of the engine.