Got it. Kinda awkward that it doesn't throw any error codes on your DIS or INPA. It does sound like a faulty MAF, but for instance, a faulty injector could cause a similar behavior. I guess you could borrow one from a fellow 3.0d owner and see how the car behaves, to make sure this is the culprit, before you throw $100+ (at least in here) at it.