Check the maf to see if there's any oil on it! If so clean it with contact cleaner and let it dry. Had this on mine very recent and the star came back with actuator code and nothing about the maf. If the maf is dodgy it with throw alsorts of codes which aren't necessarily the problem. Its worth a look.
Lol really didn't want to hear that mate.however I have cleaned the maf as you have stated and it made no difference at all.also tried to run our rev the car with the maf off and the car ran worst so I'm guessing the maf is fine. Could do with advice on the situation when the part is fitted will it have to go back to merc to be boot strapped or not or will the car come to life and be able to rev correctly.