Exhaust Manifold Heat Insulator #2

Had some rattling under the car so investigated. Turned out it was the front right break dust cover that was rubbing on the disc break when turning right and sometimes when driving straight. Was able to bend it back and solve the issue.

But in the process found two points where exhaust heat shields rusted out around bolts and were loose. The first was the rear most heat shield. Was able to get that back in place.

The second was the heat shield bolted to the underside of the exhaust manifold. The shield was totally rusted out around one bolt and the upper bolt broke off when trying to remove it.

The heat shield is off the car now. I'm curious how important it is and if I should try and get the old one back on or replace it with a new one. It would take some effort to get the bottom rusted bolt out of the manifold bracket and get out the broken bolt on the upper bracket.

Is this heat shield important to protect the rubber boot that sits below and near it (not sure off hand what it's for, the power steering/ drive shaft / etc. can be seen out of focus in foreground of photos below).

I did not see any posts specifically about this heat shield mounted on the underside of the exhaust manifold, thus I'm making a new post. If there are older posts, would love to be pointed to them.

Part: Toyota 17168-21030

See photos below.

Thanks!

Ben