Saab 900 and Saab 93 engines do not have PCV (positive crankcase ventilation) valves.
Instead, they have an enclosed crankcase ventilation system which does not require one.
The engine breathes through the filter, however, the engine has a Check Valve to keep the
boost from going into the crankcase. This Check Valve is easy to replace, requiring no
tools. The Check Valve is located under the plastic engine cover near the oil dipstick.
Note, there is an arrow on the Check valve indicating airflow direction.