What is this part?

Hello everyone, I’m wondering what this part is, it’s rattling when in drive and is right underneath the driver seat. Thank you.

 

catalytic converter

the heat shield is whats most likely rattling

 

I’m guessing the heat shield is the outside metal part. When I hit it, it makes the same sound as when it’s running. Is this an issue?

 

I had the same issue on my 2005. i tore it off. no more rattle

 

Some take it off and throw it away, some replace the hardware on it. I took mine off and threw it away.

 

but then what's shielding the heat from damage?

 

The bottom shield, no big deal. Rip it off. The top shield between the cat and the floorboard, could be an issue if removed since cats get to like 800 (F)ree world degrees.

 

Besides being annoying, no.

If you don’t want to remove the shield you can cinch it down with either a large metal hose clamp or bailing wire

 

This ^^^^^^^

Or these from Harbor Freight

 

If you ever get stuck in weeds, it can start a fire. Had a friend that lost a Fiero back in the day like that. Went off the road, drunk one night, got stuck in the ditch and was evidently reefing on it pretty hard trying to get out.
Finally walked to a nearby farmhouse to use the phone, said he was stuck. Farmer pointed back to the fire in the ditch and said, "Is that you?" Lol, complete loss.

 

I love farmers and their straight to the point talking.

 

Yep -- or just driving through dry grass or weeds that are tall enough to contact the cat.
It doesn't take much to get a fire started -- I wouldn't take the chance.
OTOH, if you never leave pavement, it shouldn't matter much.

 

I would be more concern with the undercarriage rust.

 

I agree that it's important, but you have to wonder, if it's so important, why didn't they put 1 on the passenger side cat?