22psi is where mins cycles off low freon. Put the car in the shade, open all vents, put a thermometer in the center vent, max a/c and fan speed and temp knob cold. On an 80 degree day, the compressor will stay on more than off, if it has enough refrigerant. Add some more until it will not get colder. I got 40 degrees. If the car is warm inside already it will take a long time to reach 40. Capacity on my Mystique is 2 cans and 2 ounces= 26 ounces, according to the sticker on the hood. Pressure is about 40 top of blue area on my gauge. If it loses output after that, leaks. I think mine leaks...
