1993 Maxima clunks when starting but runs smooth. No CEL. 184000 miles. After the idle slows down I get a scraping or a rattling. I am not sure. Just checking to see if anyone has had a similar experience. Thanks

 

I've been out of the Maxima game for a few years, but it sounds like a heat shield, getting resonated at idle.
I also thought I heard an exhaust leak in the second video, perhaps related?

 

Agreed it does sound like a heat sheild. Possibly the sheild around one of the manifolds or in the tunnel over the exhaust under the car?

 

could be the Y-pipe union. That union is 2 half pieces of sheet metal formed to bring the 2 pipes together and welded. Unfortunately, it heat corrodes and makes weird noises in the hot exhaust stream. My 90 GXE did that so I replaced w/ a Walker pipe from Autozone.
Or, it could be a bad bearing in one of the pulleys.