on my gti when in low revs, theres a rattle that sounds like a shield but I've check the one around that cat and the one under the turbo. but it still rattles. any ideas as to what this could be?
Could also be a failing cat. I had one go out on my New Beetle...sounded like a shield rattling so I assumed that's what it was. 6 months later CEL came on for the bad cat. No more rattling after replacement.