A vacuum leaks causes the engine to run lean.
Recently, I lost control to the air vent (so air only vent from the
> windshield, not the other outlets), and my technician found out that there
> is a broken vacuum hose under the hood near the back.
>
> After replacing the hose, all is well. Question is, does a leak in this
> vacuum system affect other systems? Because the car seems to be running a
> lot more stable now (idle speed seems to stay more or so stable at ~850
> rpm)... And I'm wondering if it's related...
>
> David
>
>