I think I read in your other thread that you have a 2000 or newer 9-3. If this is the case, you have Trionic 7 engine management which is a mass air flow based system. With a MAF type system you cannot use a atmospheric dump valve as you are releasing air that the ecu has already accounted for, which will cause odd things to happen between shifts (running rich, setting CEL etc...).
Try using the stock valve again, or getting an upgraded Forge Recerc type valve instead of an atmospheric.
Try using the stock valve again, or getting an upgraded Forge Recerc type valve instead of an atmospheric.