Hiss sound that happens after I shift?

[MC Hammered]

In first 3 gears, after I let off the throttle I hear this hiss similar to a wastegate blowing in a turbo car.

At first I thought it was due to the cracked ICV hose causing a vacuum leak. I replaced the hose last night and the hiss is still there.

The car idles fine, drives fine, but I get this faint hiss after normal acceleration and shifting. Hiss is a bit louder is I shift after hard acceleration.

I tried searching for info and found that this may be a normal sound for exhaust setups that aren't running cats. Any truth to this?

TIA for any information.

[f4tj0n]

I have a slight hiss as well.. I KNOW that one of my 2.5" V-Bands got warped when we welded it up and there is a slight leak there.. I'm thinking of running a "v-band gasket" but I havent gotten around to it.

My car also has no cats.

[dude8383]

yeh it could be a slight exhaust leak...

[raj]

I have this also. It is intermittent. I have no exhaust leaks and a catalytic converter.

[HerbE30]

Check your CCV. The m54 I thrash has a bad one and it makes a hissing noise?

Are you drinking oil like its wine?