'03 test drive. Strange noise
 

Saw a possible purchase today. Tried to do a better job of checking this one out before getting the ppi

Body seems straight no evidence of body repair , stickers were found in front and back
Miles were 46k

I crawled around under front and back best as I could - looked a heck of a lot better than the last one I saw

The concerning noise was coming from the passenger rear , like a rattling - flutter
Seemed more pronounced when down shifting. I'm thinking exhaust pressure maybe muffler. Or more likely cat converter since it was mostly on one side.
I will be getting car inspected by Porsche shop but wanted to hear from this forum
Any thoughts ?

heat shield strong possibility. The shield on the secondary cat held on by 3 spinlock bolts was my problem

If that's it no biggie. It was hot under there after test drive so I didn't poke around with hands

Possible water pump or other pully/shaft bearing on front of engine?

Loose 'brick' in cat ? Could be expensive. Diagnostic is a bit invasive but the owner may agree to take it to a good muffler shop to verify ? Split the cost of the diagnosis? Check the price of new cat first !

what would you estimate the cost at ?