3 problems with my 96 lumina first one is that it hesitates when pressing the gas about 50% of the time. I replaced the plugs wires fuel filter and mass flow sensor and it still does it. Second it blows good air when on panel setting but when u press the gas it qiuts blowing air out. and finally there is a real annoying clunk that i cant pin point in the rear of the car.

Any ideas?????????[&:]