Hi Guys....had the Engine Management Light, or Emissions Control System Light depending on who you talk to about it, basically its the little yellow engine light that came on about 2 weeks ago. Code reader couldnt reset it, which apparently indicates it is an electrical fault, hence the part needed is the intake actuator circuit which includes the v157 flap. Apparently this controls the EGR which inturns reduces fuel used whilst idling?? Anyway, on the A4 the price from Audi is £282.60 including VAT, however, the fitting is very simple and straightforward as you mearly remove the old unit via 3 bolts, and release the retaining ring holding the tubing below, and replace for a new unit. Therefore, anyone needing a new one of these, do not accept anything more than 30 mins labour time from anyone fitting the part if you do not have the confidence to do so yourself.