I get a hiss that I believe is coming from the transmission. It makes this exact sound in this video whem coming down from 3-4k revs. [yt]4KWgU22S3Yk[/yt]
Sure it's the transmission? What about the Air Injection Valves that run off the exhaust near the transmissioin?
If u don't have the stock air filters in eg pod filter could be pod filter... I know mine air filter hisses just like that.. other then that... u need a machanic