Hi guys my 2000 mazda protege 1.6l has an exhaust rattle, when you start the car from a cold start you can hear it only as low rpm. As the car warms you can rarely hear it, if i do hear it with a warm engine its only at low rpm maybe 1000 rpm. So last week i jacked the car up and banged on the exhaust and i couldn't believe. As i banged the down pipe i believe its also called the resonator I hear the exact same rattling that i've been hearing. But here comes the intrested bit where i bang on the down pipe there is a exhaust shield right where i bang the down pipe and hear the rattle but the thing is that the exhaust shield is not loose its tight. So what do you guys think it is that's making the rattling noise? If its the exhaust shield what do i do, replace? and if so where do i get a new one from as searched online and don't see anything

Here is the video:

 

Sounds like a baffle came loose. Is that a one piece system? If not, you could remove a section and see if you can shake something out. Either way, you'll have to replace that section to eliminate the noise.

 

from looking at this diagram. No.5 where the exhaust shield is at, at the down pipe/ resonator is where the noise is coming from but do i have to really replace that whole part? because it funny the noise is only come from the exhaust shield area no where else on that pipe.

 

I would check with a local muffler shop. They can probably cut the resonator off and replace it. Personally, I might have the muffler shop just put a straight pipe section in and eliminate the resonator. You'll get a "sporty" sound from the exhaust but it shouldn't affect drivability or emissions testing. Otherwise, your going to have to buy the whole section.