I am posting this in the exhaust forum because I firmly believe it is the exhaust doing this.

My setup:
revised VQ35DE (one year old replaced under warranty)
Nismo S-Tune catback
Kinetix V+ plenum
JWT SRI.

Ever since (lol I know dealerships hate hearing those two words) Nissan replaced my engine my car has been smelling funny under load ie. going up a hill. It has that rotting egg smell. I know this is the cats doing their thing but here is the weird part: When I had to replace my kinitex V+ plenum I had to put my stock intake on. Smell went away.

So when I got my new Kinetix put back on, the smell came back. But that wasn't the ONLY thing. And this is why I'm posting this.

An odd exhaust sound has started. I got it checked TWICE for leaks and its solid. No holes, no leaks. It sounds like a freaking Honda Civic, all rasping under WOT and its louder in the cabin. What could this be? No codes, no CEL, but the sulphur smell is back under load and WOT.

I want to post a video showing what this sounds like. Could this be a broken baffle or catalytic converter going, or a resonator blown, etc. I don't know. It sounds HORRIBLE.

Its like someone stole my Nismo exhaust and replaced it with an Ebay muffler.

PS My exhaust IS old, its one of the first Nismo exhausts ever built (installed on an early 03 before I bought it)

Thank you guys!
HAPPY NEW YEARS MISS EVERYONE!!!

Darryl

 

rotten egg smell is a sign of hydrogen sulfide, a byproduct of the cats. I had it happen years ago with a car and it was caused by the car running way too rich.

 

Could running rich damage the cats without causing CELs? Could it be my o2 sensors too?
How can Nissan adjust this?

Sorry for nubbish questions. Thank you for your quick reply Dave

 

The sulphur odor may be caused by:

a. Failed catalytic converter.

b. Catalytic converter is operating properly, but unable to burn all spent fuel. You may be running a low air/fuel ratio.

c. Switch fuel.

 

I run only 94 octane from Chevron, but thing is the smell goes away when I put my stock intake manifold on. So with the V+, can it be too much air, too little fuel?

Wouldnt a failed cat cause a CEL? meow.

 

A failed catalytic converter SHOULD give you a CEL.

As DavesZ#3 mentioned you are running too rich.

 

Would this be easy for Nissan to adjust? It goes back in this week. I'm sure they'll have an air-to-fuel ratio monitor.

Thanks davidv

 

03 will probably not throw a CEL for bad cats. You can run test pipes on an 03 without nonfoulers and not throw a code.