It is possible that the injector cleaner loosened up some stuff and it is causing the engine to run even worse.
But IMHO, fuel injector cleaner is crap. It will probably just clean out your fuel filter more than your injectors. Redline Fuel Injector Cleaner is the only one I can say works. The true way to clean them is to simply pull the injectors out and blast the cleaner through it (professionals only).
Lance put together a nice how-to on replacing that stuff. Try it.
One last thing -- the throttle body and intake manifold might be dirty. That caused some poor throttle acceleration on mine.
