BOOST BUCKING PROBLEM

Thanks to Joe Truckenbrod for contributing to this FAQ!

I had a boost problem with my car and had no idea where the problem was coming from. It would boost then bog down, boost then bog down and so on and so forth. Very hesitant on hard acceleration. It also would only boost from mid yellow to 3/4 yellow max. I thought fuel cut off was kicking in because thats all I was able to find on my searches. Took it to a saab shop and they determined it was my air mass meter. Replaced it and an wow what a difference. Keep in mind that we have not seen the airmass meter cause this problem often but we have heard of it happening in some cases. What happens is that the filament in the meter is failing which indirectly causes readings to the ecm to be incorrect.

Another very common problem is the Boost Solenoid (APC Solenoid) failure. When this component fails the Turbo will overboost causing the fuel the pump to cutout.

Thanks to Chris Prather for contributing to this FAQ!

I bought a 97 900 Turbo with an overboost problem and was told the wastegate had been adjusted to much. The car was way too clean to have been "messed with" too much. Upon further inspection, I found the wastegate hadn't been adjusted at all. In fact, the wastegate wasn't moving period. It was corroded in place. I simply worked it back and forth several times with a pry bar and small hammer. Moved easier and easier each time. It works like a charm now. Saved buying a 200 dollar boost solenoid.