Air flow meter (AFM) is usually I good place to start. Does the car feel like it is surging with the power coming on and off, with a hesitation in power delivery at part throttle? A bit rough coming on and off the accellerator? Using more fuel than normal? Is the car ok to begin with, then gets worse as it warms up while driving?

As the guys said, give us some more details (using proper grammar) and we might be able to help you out.