Same thing on my 06 H3 I noticed it to be the stabiliTrak when your truck slips it adjusts hence the smell-I put it through a test yest. in about 5 inches of snow left my stab on while cutting it up in a big empty lot sure enough same smell then i did the same test with the stab system off and sure enough smell gone long story short I think Its a lovely smell as long as we stay safe! HAAAA!

 

cept, im going out soon to go watch da bears.
the instant i start,without moving 1 inch, i will smell it. its the exhaust, processed by the cat,,,youll see!!

 

it's not the cat...

 

funny,i walk around h3 cleaning sno,,,no smell. start eng,,instant smell, i know, its my lilacs thinking spring!!

since there is no egg smell anymore i assume the cat design is changed,new nice smelling metal!!

 

I noticed the same thing on mine my '04 H2, and thought it could be the cat's(smells was very strong after a highway run) cause i could smell it inside the cab with the dvr window down doin abbout 80k/hr

 

I also have the smell, I notice it every time I drive in reverse up in my driveway, I have a 2006 H3, never could find the issue, I have had it for about 3 years and still have the smell.