Did you ever figure out the final solution for this issue? I think I am having a similar issues on my 2010 Subaru Outback. Thanks.Seems that will be my next step via the dealer I think... I read on other forums that the idle can be raised but has to be done via the computer / diagnostics being hooked up. So me adjusting those screws on the throttle body will not help as the cars management will just try to compensate I guess based on parameters that have been set.
Once I know more or find a solution ill update this thread.