ok, so i just finished putting a 4-2-1 header system on my D-16Z6, and now when i drive it, i hear a hissing sound comming from under the car. The exhaust isnt as loud as it was before because of this hissing which sounds like air escaping or something. What could it be? someone tell me cuz i havent got a clue.

 

exhaust leak? just jack your car up, run it, and find the noise.

 

it was on jacks earlier, and i still couldnt find the noise. It doesnt give the noise when its in neutral, only going through the gears puttin rubber on ground

 

Have you put a exhaust gasket in?? its like a little mesh o-ring??
My friend has just fitted a OBX 4-2-1 header on his h22a prelude and his makes the same noise, we thought it would be a gasket so we put a new one in it, checked the header for any cracks etc and it still does it. cant hear when on jacks either so it one of two things.

Either the header just sounds that way as gases pass though it, or its leaking but only when under load (actually driving the car, and not just reving free on a ramp/jacks.
Good luck anyways

 

Hissing sound? Is there a pissed of snake in ur exhaust.