Hey guys new to this site, I have recently picked up my 2007 A4 Auto/ Tiptronic Quatro.... That same day on Sept 8 went and got it chipped with APR. Everything since then has been great, good power and very fun. Today I was driving home from work and see that my CEL goes on and it seems like (maybe its just me ) that i have lost some power that I experienced before, otherwise the car is driving perfectly fine.
I took my car to the dealer for CEL and it came up "overboost/dv". They reset the CEL and i drove the car hard and it came on again. Who makes the best DV for my car and where can I get it
Any idea what this might be? Thank You in advance

Here is an update on my situation with the car.... Yesterday I took my car in to the service shop due to the CEL and was told that they need to order a new wastegate valve because my seems to have an internal elec. malfunction...part should be here tommorrow. Can anyone tell me what exactly does the wastegate do?? and does this effect the loss of power that i have experienced. Thank You in advance