I have an 03.5 g35 with 123 xxx kms or about 74k miles.

Ive noticed when i floor my car a few seconds after i let off it smells funny inside,

Ive also noticed this when going up long steep hills, Smell is stronger when flooring it then when going up hills.

Kinda smells like eggs/ burnt toast? I'm guessing my cat may be loaded up and it could be burning off when my egt's get up. the other possible option could be my trans.... im hoping its just my cat.

All maitnance is up to date, All regular oil/ fluid changes have been done on a regular basis.

 

Rotten eggs is sulfer smell.

It's usually a byproduct of combustion when using fuels with high sulfur content.

Try a different gas brand or station to see if the smell goes away

 

I was told by many it's my cats. ive noticed it with different octanes and gas stations.

 

If it's really excessive it could be a failed cat....especially if it's been driven a while with a CEL on indicating a failed o2 sensor.

 

yeah i havent had any CELS though. I had the extension for the o2 sensor to elimate the light.

 

No CELS here, the smell is not even that bad, My gf said im crazy cause she couldnt smell anything, I was just curious as to what was causing it, and if it was a sign of something bad to come. Oh and i allway run 94oct gas.

 

oh ok. maybe cats are going bad, i have no idea. still havent figured mine out lol. but my situation is similar.

 

Sunoco? They are known for high sulfur content.


BTW, there is no benefit to 94 if you don't have a tune and are N/A. You aren't making any more power or fuel efficiency over 93 or 91 octane...it's just wasting $$. All you need is 91

 

Interesting... i never knew that.

 

Husky 94 (canada) and ive noticed 2-3 mpg running 94 over 91, it also burns cleaner, and leaves less carbon build up. I over maintain all of my cars.

 

yeah i know how you feel about that over mantainence lol.

 

Well, if the smell is REALLY bad, then its prob a failed cat but the big question would be why did it fail? It usually does this as a result of a slightly rich tune. That is why i asked about any O2 related issues.

If it's a minor odor, then it could just be fuel which has high sulfur content. I do notice my G does have the smell when i first start it, which is normal for cold-start up, but doesn't when warm.

 

I have the same issue. Rotten egg smell during WOT. Mustang is correct.

 

It's normal, and it's your cats. I have 3" HFC's and they stink BAD every time I go into boost. Feel sorry for the people behind me.

If you still smell it with your windows rolled up and on recycled air, you have a leak somewhere that you need to get fixed...

 

like everyone said, its most likely your cats. are you stock? did you replace with hfc? or you might have an exhaust leak as well.