Its not the normall sound, its a different sound that happens right at 2900rpm for a second

 

Exact same thing, though i notice mine once it's warmed up...after 30 minutes or so driving. I occasionally get a CEL though i can't tell if it's related as I can have the rattle/power loss with no CEL. Other times i get the CEL for no reason at all...

Been dealing with crap for over 2 years now...I still don't understand how people can design something then not figure out whats wrong with it....w/e

 

Only for the past 2 or 3 days my car makes a sound like tiny metal bits being bounced around inside the exhaust. This only seems to happen from about 2-3.5k rpm. I recently installed an agency power dual resonated midpipe so obviously.. not a cat issue..

 

Bro,have u settle this problem?

 

I went to the Mazda dealer today and had this problem looked at. The mechanic told me it was the catalytic converter and he heard about it before. I went there to get my rear brakes done and he said he'd check it out. So while I was sitting in the waiting room service manager comes out to tell me he's got good and bad news. The bad news was I would have to wait care for three hours. The good news was that its the catalytic converter and it's still covered under warranty. So after three hours of waiting I paid my bill got in my car and it was silent as all hell. I've been driving around with that sound coming from the undercarriage of my car for the last two years thank God it's gone. So I hope this solves the mystery and all you guys get your car fixed trust me it's well worth the wait and well worth the expense even though mine was free. It saved me nearly $1800 still being under warranty.