My 99 altimas check engine light was on so I had it checked and turns out to
be a bad IAC valve so i buy one and install it and now I have a high pitched
whistle coming from it. every thing was installed the same as the old one
the hose and 3 plugs are connected. Im at a loss I really dont want to have
top take it back out if I can help it. Any help appreciated Thanks
TOM

Sounds like a vac leak at the bottom of the IAC and intake.