When I am driving around the city I can hear a hissing noise coming from underneath my car. I brought it to a local exhaust shop and they told me that my car had "no leaks" in my piping.

WHat else could be the problem?

 

Do you have an aftermarket intake? Sometimes the intake will hiss, and its covered by the OEM intake.

I have the same problem, but I'm almost postive its a leak.

 

Yes I have an aftermarket intake, exhaust, and header.

But it seems like it got louder. Especially when I hit VTEC, it feels like I actually lost power right when VTEC kicks in.

I dont know, but a few days ago I was hearing some kind of rattling noise from somewhere and then all of sudden it disappeared. This was when my VTEC started to act up.

And no exhaust leaks.

No CEL or anything.

 

do you have a hesitation or rough idle, I am going to guess a potential vacuum leak.

 

is it throttle position related or does it hiss all the time?

 

throttle position only

 

No hesitation or rough idle.

 

mine hisses when its between 21k-28k. after that theres no hissing. i have an i/h/e.

exhaust shop says i have no leaks either.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Inextricabledrvr &raquo;</TD></TR><TR><TD CLASS="quote">throttle position only </TD></TR></TABLE>

mine hisses from about 20-30% throttle.

its likely just the throttle body. You can take off the throttle and make sure none of the gasket is sticking out in the path of the airflow.