Engine Performance problem
1991 Ford Taurus 6 cyl Front Wheel Drive Manual 157000 miles

I have a 1991 ford taurus SHO 3.0 v6 24 valve. When you hook my car up to a computer it says that theres a problem with the MAF. But my MAF is brand new. So i thought maybe it was the air charge temp sensor but it still does it after i replaced it. It only does it when its warmed up. if i hit the gas hard it doesnt hesitate it goes fine and quick. but if i just hit the gas lightly or normal it hesitates bad. What is my problem? Please help