I agree, it is probably just fresh cat you are smelling. They are supposed to make a sulphur-like stink when they are new. Some people call it "that new car stink".

Fresh Cat smell even after nearly 20k miles?

Anyway, I think the IAC was the culprit. Every time I moved it or tweaked it or changed my air intake over the last week I got the sulfur smell...

-I cut a vent into my fender (its damaged anyway....) to let in more air and the car stunk on the first hard acceleration
-When I first changed out the sensor for the new one the car stunk
-When I moved the position of the sensor the car stunk

It didnt smell on acceleration after I had ran the car for a while without moving the IAC (I'm assuming the ECM adjusted for the changes).

Anyway, I modified how I had the sensor mounted today. I have a cone filter with a metal collar leading to a plastic tube running to my intake. I drilled a hole in the metal collar and used the old sensor to tap threads in it. Heres a pic of the old sensor... its kinda nasty looking:





After this change I did get the smell one more time with the new sensor, but I imigine its because I changed the location of the sensor yet again... Assuming it doesn't smell again, then I think I can definitely say it was the IAC. I'm still going to try to spray down parts with carb cleaner and see what happens though...

Still getting the sulfur smell. I'm tempted to just toss in my stock airbox or totally redesign my rigged CAI.

Any more thoughts? Could something with the evap system cause this?