maf sensor signal voltage

[bazer1]

have a corsa b 1.2 16 v x12xe engine 99 year , its my daughters car , having trouble with eml coming on at high revs etc on moterway its fault code 0130 o2 sensor low voltage, its holding back as well but im sure the maf sensor at tickover its 1.5 volts bit ar wide open throttle its about 2,2 volts acording to the bosch tech sheet should go to at least 4,5 vots does anyone have the voltage for this at wot thanks baz