The sensor at the actual airbox, immediately after the filter, is definately a MAF (Mass Air Flow) sensor. The MAP (Manifold Absolute Pressure) sensor is attached the the intercooler hidden under the passenger side wing so-to-speak, so if they said the one at the airbox is a MAP, and thats the one you unplugged, then they are talking complete ******. Keep your £90, and put it towards a MAF, because you rightly diagnosed that it runs perfectly, better even, with it unplugged then that shows it is giving incorrect info to the ECU and is faulty.
You can try spraying it with carb cleaner (not while running!!!) and its easy to remove to do it right.
Take it off, you'll see a sort of cross-hair gun sight bit - thats the sensing element, its a Hot-Wire Anemometer type, that measures the cooling effect of the air passing over it, so when it gets gunged up at all from filter oil, or any contaminant, because its hot then **** "cooks" onto it, so that it then gets coated with a yucky film it cant cool so incorrectly tells the ECU the airflow is WAY lower than it really is, resulting in weak fuelling.
Try cleaning it - NO CONTACT with the element tho, just spray it until all the crud is removed and its sparkling inside, then try that, if that doesnt help (and it will most times) then the element is ****** and just buy a new one from
www.vagparts.co.uk -
if as you say your consumption is heavy, perhaps yours is busted, and the ECU thinks the airflow is much higher than it is, so cleaning may not help your problem.
Search for MAF or put your MAF part number in....heres the one for example that fits certain engine codes (not mine for instanceas mines a BFB engine)
https://sslrelay.com/s74326199.onea...shopscript?article=0020_MAF+=2806A906461AV=29
(its still vagparts just thats the url they use to load the page)
Its about £90, replacing a faulty one will put the DTC light off and the car will be fine, if its still running badly then you can get a refund and get a diagnostic then, but your likely right about it. Remember try cleaning first, its an OLD problem dating from MK3 golfs onward.