So I have a 2004 Infiniti G35 6Mt and under hard acceleration I get a weird smell but when I drive normal it doesn’t smell smells like a clutch but I don’t believe my clutch is bad so just trying to see if it is my clutch or something else maybe a Cat?

 

Cat will smell like rotten egg. If you suspect a slipping clutch (which is what I suspect) get out on the highway in 6th gear, preferrably on a slight incline, punch the throttle wide open and watch your tach, if there's a slight blip where the rpm's jump then fall back down and it's not 100% locked ratio to the speedometer then your clutch is STARTING to slip.

If this is the case just be super aware of it and don't go mobbing around recklessly or you'll give it a quick death stroke. You can limp a slipping clutch along for about a year if you're being really careful to not overthrottle the thing and cause it to slip more, that way you can schedule the repair on YOUR TIME rather than it failing quickly and you're stuck doing the repair NOW.

 

Good advice.