Celica will only start if gassed

This happened the other day and I'm still
trying to figure out what's wrong, the car
limps around, it has a terribly rough idle at
around 200 rpms and it will stall in neutral.
It won't even start up unless I floor it and
the engine is sounding different than it was
a few days ago. I've replace the oil,
coolant, and sparks. I checked the
injectors and they're all pumping fine. The
CEL came on but I have no way of
checking it at the moment because I don't
want to cause more problems with this car.