I have this noise from the front of the car when i start it up, and usually lasts for about a minute, someone else before described it as 'pins dropping in a can'. I went to the mitsu dealership today, and it was what i suspected, the flex pipe is defective. If you are having this problem, i'd suggest getting it in to the dealership and having it replaced, they told me it costs $1080CND for the part, although it is covered under warranty and will cost me gas there and back. OH and they didn't give me any hassle about having an injen cold air intake, or axle back muffler in case anyone was wondering.

 

My dealer is the same way no issues with the intake and exhaust.

I need to get my flex pipe fixed (replaced) 1020 seems a little retarded.

 

Yea i brought mine in to the dealersip last week for the same noise... and it was the same problem. Getting my new parts put in on tuesday, free of course! Yea and they didn't care about my axelback either.

 

I already had mine replaced once and it is doing it again... same with my throw-out bearing...