Hello all I'm new to this forum, as well as the new owner of this 99 a4 1.8t, I need help in identifying what this part is that is located under the throttle body. Appears to be a rubber diaphram, I'm getting a "honking" noise under load, already replaced the dv, did a boost test (no leaks), as the "honking"sound happens I lose vacuum (per the autometer vac/boost gauge), as I ease up on the throttle the vacuum returns. I suspect this part. Any help would be appreciated. The car is bone stock.I tried loading a pic but can't figure out how to.