The Vibrating Accord

Hi everybody, i have a 93 honda accord ex/auto w/ 176,000 and the problem i have today is that the car idle's fine in drive and in park, but when you put the a/c on, especially in drive, the car with drop from 750 rpm to almost 100-0 rpm when i stop,basically shaking the car. but when i take off again, the car is fine, its just when im stopped in drive and in park. Someone told me it could be the mapp sensor, but i need some help. Its a free message at every stoplight but i think the car doesnt like it. Thanks.

Mine does the same thing sometimes. I heard it's the AC idle up VSV. Don't have time to look into that yet. Maybe this is a good start point.