Komradekozik

is the idle stabilizer valve under the intake manifold about midway, can it be removed to be cleaned without removal of the intake manifold.

PorscheDoc

If it is still attached to it's rubber mounts, then no, you have to pull the intake.

Komradekozik

how can i tell if mine is bad, any notable symptoms

lleroyb

Check out http://www.Clarks-Garage.com , if you own a 944 this should be one of your favorites.

Look under "garage shop manual" then look for "idle adjustment".

It also has a great write up removing the intake, if you choose to do it.

Lou