My 2015 gt has around 1600 miles on it now. At around 900 I started noticing a random rotten egg smell coming from the exhaust. It smells like the cats. At first I thought maybe some bad gas was my problem but i have since filled up twice at different stations and still randomly get the smell. Car runs fine otherwise. I took it to the dealership and they said it was normal on a new car that it would go away as the converters wore in. Just wondering if anyone else has had this problem

 

that is normal to smell from time to time, its a sign of the cats doing their job, you will notice that you smell it after a hard acceleration, that because the air fuel ratio goes a bit rich then and the cats will emit a bit of sulfur, nothing to worry about

 

Will it get better as the cats get some age on them. I get it when cranking the car and sitting at stop lights without getting on it hard from time to time as well

 

not sure, but i just checked OASIS and there are no exhaust smell tsb's for the 15 mustang, so ford doesnt have a known concern.

 

Also always buy gas from a tier one station, I like Chevron, never buy cheap gas trying to save a buck, it's not worth it in the long run.