Has anyone replaced this valve? What are the symptoms of it being bad ? The shop told me that I have a code set for "intake manifold vacuum correlation" Been trying for 2 months to find what the issue is causing lean codes on both banks, and this is the latest they came up with.......but they don't know what it means.......just grasping at straws as to what the issue really is......Thanks for any input you can offer. Engine has been smoked twice, vanos checked, intakes blasted, new valve cover, map and boost sensors. Engine is very clean inside.

 

It should be at the front of the engine take it off and blow through it. If you can blow easily replace it. I had to replace mine but was not getting the error you got. Do you know the actual code the car is throwing

 

Also, you should be getting lean on one bank if it were the vent valve.