Often it is the TB.
There are 2 02 sensors and fairly easy to replace.
A failing DIC will usually toss a code but in early stage normally will not make idle rough.
A TB can be removed for cleaning the electrics under the cap. Very often helps. Some can do it while still on the car.

 

Also check this thread out:

http://www.saabcentral.com/forums/showthread.php?t=418417

 

Thanks Mike,

I will try to clean the TB and check the PVC valve today.

 

I checked the PVC valve today, it was stained inside but had no signs of a blockage.
I looked at the top of the TB, it had carbon deposits that i removed around the opening and the valve, but there more more inside i couldn't access.
Idling seemed a little better but is still a little rough.

Also there is a lot of vibrations on the steering wheel at idle when in drive? Could this be a issue with the steering?

 

A couple of things. The TB needs to be removed to clean it properly with TB Cleaner. Nothing else should touch it. Then under the black cap electric contact cleaner and a soft toothbrush. Another issue is that you have 3 motor mounts under the motor, plus one under the that big par holding the motor up at the top right side and another unit on the right side of the transmission. If any of those are bad they likely all bad. Steering does not create vibration. There are also sub frame bushings that fail. Best to get them checked out by someone who knows what to look for. If your motor is bouncing around or if it moves a lot when you rev it up that is also a sign of bad mounts.

 

Thanks Mike,

I will organise to clean the TB properly,
The engine mounts were tested by my mechanic and seemed to think they were ok.

Some else suggested "timing chain wear" or the "balance shaft chain wear"

is there a way to check for these?

 

The timing chain rattles, especially on start up. So if you dont hear it it likely is not that. Make sure you vacuum line under the turbo is in good shape