lack of power and stalls

what can cause this car to run so poorly all of a sudden,car runs but no power,you must acc very lightly,it will run then it feels like it shifts into fourth gear and it chokes and stalls.This happen when you first start and engine is cold, after it worms up you will be able to start engine but not drive because the condition get worse as soon as you put it in gear it stalls,found 5 codes,PO304,421,431,725,750. codes PO304 just came up but i dont fell a miss,the other 4 code have been there for 3 years.i know what thay are.If i disconnect the mass air meter flow the car runs even when its hot, Tried 2 new mass air flow meters but still the same. I drove the car about 20 miles in the city on highway and run perty good,but poor accelaration.