Was wondering if you guys here hissing swishing sound that sounds like a exhaust leak when accelerating?

I don't hear it inside but when I put the windows down I do and it's annoying because it makes it hard to hear the nice exhaust sound and was wondering if this is just common with the g35 sedan.

Also, could this explain why i have been getting on and off the P0420 catalyst code? The noise is coming from the the middle of the car where the Catalyst is...

Possible gasket leak?

My g35 coupe didn't do this.

 

do you have an aftermarket intake on the car? i get the hissing sound but its from my intake. otherwise get you car up in the air and look if there is any built up soot from any of the exhaust joints/ gaskets. and replace as necessary.

 

No after market intake or exhaust. 100% stock.

And I'll get under it and search for soot.

 

hissing is intake.

An exhaust leak makes a ticking sound.

 

It's more of swishing sound then hissing.

It's going in this weekend to double check. P0420 code hasn't shown up in awhile but it's still stored so if its a leaky cat gasket, that could be reason for the swishing noise when accelerating.

 

I know exactly what sound that is. It comes out from under semi-hard acceleration from under the car everytime I pull out of my work's parking lot to make a u-turn for some reason. EVERY time. And to the best of my knowledge nowhere else. I'll usually pull out slow onto the street down the driveway (steep) and then smash quickly to change 3 lanes and thats when it comes out. I suspect it has something to do with those particular circumstances (maybe RPMs or the way computer reacts to sudden push from a roll) because it comes out every time and nowhere else...

 

Just got it back from the infiniti dealer. The cat has a dent in it and needs replaced. Covered under warranty. That could explain the louder than normal exhaust. Hopefully this fixes the issue. I will keep you guys posted.