Hi there,
The MAF on my 1.8T was clearly on the way out. I was getting flat spots during acceleration, so I cleaned it and things improved a little bit, but I decided to get a new MAF to sort things out once and for all. I bought one on ebay from the Portland Group. I fitted it without any problems, but the car runs like a dog. The revs won't settle when idling and the car generally stalls. When I hit the throttle, it's flat as hell, as if I've got the handbrake on. Nothing happens for about two seconds, then the revs go through the roof. The car rockets down the road, occasionally kangarooing violently. As long as the revs are up, and it's not lurching along the road, it seems to have much more power that the old MAF, but clearly I can't drive it like this. I put the old MAF back in straight away and things are okay again, although obviously I still have the old flat spots.
Is this new MAF no good? Does the car need to 'adjust' in some way? I heard that if I disconnect the battery for 30 mins, the ECU will some how adjust to the new MAF. Is this right? If so, does this mean that my car actually recognises its original MAF and knows if there's a new one in place? Also, someone said the throttle body needs cleaning, but if that was the problem, the car would be a dog even with the old MAF, wouldn't it? Any help would be appreciated.