My saab started stalling (the engine acts as if it stops running, and then starts running again). This causes the rpms to fluctuate (sometimes going down 1500 rpm before coming back up). However, if I let the engine idle, there is no stalling. The longer I drive it, the worse it gets, until it stalls when slight pressure is applied to the accellerator. When I turn off the car and start it back up, it runs normal for a little bit. This problem has been getting progressively worse and now the car isn't driveable.
Also, when the accelerator is pressed hard from idle, there is a dip in the rpms. However, when in park I can raise the rpms to any level and it will stay there without fluctuating.
The computer is throwing the code P0108, the map sensor is showing higher pressure than expected. I have replaced the map sensor and all vacuum lines connected to the throttle body (they were in bad shape). After doing both of the above, the car seemed to work fine, then 30 miles down the road it was back to the same problem. After this I started throwing parts at it, and replaced the fuel filter, the fuel pressure regulator, and the spark plugs, I also cleaned out the throttle body. These had no effect. Just now, I used a baby snot bulb connected to turbo bypass valve to test for leaks, but it didn't seem to be losing vacuum.
I'm tearing my hair out on this one, and hope you can help. I have a feeling it's something very simple, but all of my research and attempts to fix it have been dead ends.