Should I replace this part or not?
 

I was under my car today doing an oil change and I noticed what looks like a "shield" on the catalytic converter?? I'm guess thats what it was, the "shield" goes over the cat coverter (had a sensor or something sticking out of it), the shield is held on with a bolt at each corner, one of the corners had rusted through and iscame apart.The other three are rusted but still in place.

Should I replace this "shield"? What is the actual name for it so I can quit sounding like the newbie I am?

RE: Should I replace this part or not?
 

You should put your year/model in the signature so we know what accord you own.

It is called the head shield for the catalytic converter. It prevents the excessive amount of heat generated in the cat from catching grass on fire if you park over it. It also prevents heat from getting to the under body of the car. Its not hard to replace, but those bolts are going to be pretty rusted. I had to drill through the head of the bolt to get two of them off. Keep hitting them with PB blaster to get as much rust out as possible. You might want to put a socket on top, because that welded bolt may come loose too.