If you unplug the MAF and the car runs well, it means there's a leak. There's a small chance that the MAF sensor itself is bad but the odds are 99.99% that it's a leak.
Since it affects idle I'll put my money on a vacuum hose. Check the notorious T under the intercooler and all the other vac hoses you can find. You may be able to hear the leak while the engine idles.