My IAC leaks vacuum at the plastic cap on top and you can here it in the car hissing going down the road when you dont have a load on it... Is this normal??? do i just plug it there??? what to do?? do i need a new iac???
Are you sure thats where the hissing is coming from? Aftermarket CAI's will make a hissing sound. I hear mine all the time. But if your IAC is leaking, I would replace it.