the ac in my 98 coupe is not cold nor is it hot. before i recharged it i tried using the ac and it was blowing out regualr temp air. so figure that the auto shop released all the freon. so i recharged it with the r134a canister from autozone. i put just about the whole can in it. the can was about the size of 1 1/2 soda cans. but for some reason the ac is still not cold. do i need more? and also whenever the ac is on i hear this noise coming from the passenger foot well. where the ac unit is. its like a high pitch sucking noise. kinda like a vacuum.