were the new injectors a performance aplication (bigger injectors)?
I assume they were, it seems like your car running rich (getting too much gas for the amount of air you're getting...)Thus the reason a bigger air filter helped, and accounts for almost stalling, in fact by what you describe I would bet on it, you slam the gas, the air intake can't keep up with your beefed up injectors dumping gas in so quickly...
So to fix your intake problem... get intake (e-bay's cheap),
and go ahead and bore your throttle body out while its out, heres a link
http://www.qksltwo.com/tb.html
I did this mod (see sig.) and I was pleased with the results, plus its free or cheap depending on what you have around the house saves you ~$150
cleaning your throttle body out with carb cleaner as sierrap suggested will probably help the problem
I would suggest removing the throttle body to do this (be careful removing the gasket, a torn one will cause you to go on a hunt for a new one) after removing your IAC sensor, spray the TB down real well with carb cleaner (move your throttle position while spraying) while its out clean your IAC sensor,
I bet after you do both of these it will roar to life as soon as you hit the gas and be another Saturn success story out there, they're quick if you make 'em quick
