Has anyone noticed smoke coming from the exhaust?

I was following my wife home from the dealership today and I noticed that when she floored the car a light brown smoke came out of the exhaust. It wasn't a blue colored oil smoke, but a pale brown. Any ideas what it could be?

 

Black Smoke indicates the car it runnig too rich. I was told that sometimes others have noticed mine puts out a little black smoke. 08 MCS w 24K.
Blue or white smoke - not so good.
http://www.myhonestmechanic.com/arti...tailpipe.shtml

 

Brown I would take it in could be a number of things.

 

Brown smoke can come from the catalytic converter if it sheds a layer of rust. In that case it is actually fine rust particles and not smoke. Try putting a rag near the exhaust tip, get your wife to blip the gas pedal and see if it leaves any rust particles on the rag. Cat converters are typically covered longer than regular warrantees because the government requires the manufacture to cover them.

 

I would say it is carbon build up being burned off if she floored it. If it does it under light acceleration then you have something to be worried about.

 

It only happened under WOT, doesn't smoke at all normally. We're going to a Mini rally on Sunday, I'll have a chat with the MA/Tech and see what they say. (No CEL by the way).

 

Sounds good have a great time and let us know what the tech says.