#2 cylinder lean and unstable boost?

ok im very new to this forum and also kind of new to the saab diagnosis world. so heres my delema. i own a 95 9000 aero. 2.3 turbo manual trans. the car has 132,000 miles on it. ive noticed a misfire at idle. i pulled out the plugs to inspect them . the #2 plug was way lean! so lean it was mealting the outer electrode. i really dont want to keep running it this way damage to piston is on its way. i checked for an intake leak accociated with that cylinder. none found. i checked the fuel injector resistance and it showed the same as all the rest (dont remember that value off hand) not sure where to go from here. DI cassete was replaced at 85,000. my second problem is this. the car does not know how much boost to make it seems like everytime i drive the car it makes a different amount of boost. its not really case specific though. it seems like it just decides when ever it wants too make full boost. sometimes it will only make 1/3 the yellow line (base boost?) sometimes it will go all the way into the red i mean all the way as in nearly off the gauge. shouldnt the fuel cut happen at that point? the blow off valve just got replaced, the boost pressure control valve moves in both positions. no vac leaks? what next please help i cant afford to burn up a piston . but its my only car so im forced to keep driving it. any help is greatly appriciated.

have you tried doing a fuel injector flow test? i am not sure what tools you have at your disposal, but you may want to take the #2 injector out and clean it really good and try that.