2009 Ford Mustang Throttle body/Check Engine Light

I recently Installed a 70MM BBK Throttle body and my check engine light came on. There is almost like a whistling noise as I accelerate. So people say it could be a vacuum leak, some say it's because of the new throttle body. I've even put the stock body back on and still heard the noise so I'm pretty sure it's a vacuum leak but cannot find it. Also, my exhaust is leaking now. Not in idle but when I accelerate then let it sit you can see it leaking from the chamber. Any Ideas? Thanks in advance.