Funny Noise
 

I just had a quick question. When I start my car it sounds fine right away. Then it starts making a funny exhaust noise from under the hood, but only for like 30 sec. Happens every time it's cold. I've never had this problem before, and it happened when it started dropping below zero. Any help would be appreciated.

Bruce

Secondary air pump. Pumps air into the cat to warm it up on cold startup. Perfectly normal.

Thanks
 

I used to me a part time auto mechanic, so I thought it might have something to do with an air pump. It sounded like a valve. Thanks that helps me alot.