First you need a tune ASAP. You are more than likely overboosting then the ECU is going into limp mode. Also I would HIGHLY suggest you buy a boost gauge. The moaning could be a lot of different things but if you have the stock DV I would start there as it's probably dead. Last is you have a 99 so no you do not have a map only 00-01 A4's came with the MAP on the intercooler which makes it possible to do the diode mod.