What's this part called? Hanging metal piece in undercarriage.
 

Today I was driving and all of a sudden I hear a grinding sound. Went under to check and this piece underneath was hanging there. I don't know what this part is called so if anyone can help me with that it would be great.

I know this is not a g35 undercarriage but it's basically the same part connecting the exhaust system.
Attachment 262139

Those are your catalytic converters. Is the heat shielding around them coming loose?

yes I believe the heat shield is what came loose. it's the outer shell of it. Thanks

Rip it off, Or replace them. They are fairly cheap.

My G started making a raspy loose noise from under the car. Could this be the culprit? When you say rip it off...are you referring to the cats, or the shields? Also...I smell something like rotten eggs every once in a while. I've heard that's a sign the cats are going bad.

Shields..

How are the heat shields connected to the CATS on our cars?

Are they welded at the corners, or screwed in?

My Tacoma has its shield connected by 4 screws to the chassis of the converter. These screws are very prone to rust since I live in the Northeast in the rust-belt. About once every 2 or 3 years, I need to climb under there and pop out the rusted out old screws and replace them with new ones. I need to put some stainless screws in there next time, but usually it happens in the dead of winter when it's cold as a witches' tit out side, and I just grab whatever screws I can find and pop them in as a quick fix.

They are spot welded on.

Either rip them off, or get some hose clamps and clamp them on

The smell you refer to generally means your cats are becoming plugged, have a muffler shop check em out. Converters or their covers unless damaged/lose do not make noise! If you have a cat cover lose, again have a muffler shop weld it.
Gary

Lol i can't help but feel this is a troll thread...

Gary, just seeing your message now. It usually makes the noise when I gun it. It randomly smells like rotten eggs, usually at idle or once I turn it off in the garage. I'll get with a muffler shop and see what they find. Thanks.