I checked the vacuum and it was steady at 20"hg even when I wiggled all the
tubes & ducts I could find. My car is a V-6 (1998 North American model) -
there seems to be a vacuum switch that then branches to TWO "regulators"? I
measured the vacuum at points A & B of what seems to be a vacuum switch - It
was always about 20" at A. At B it was 19" during warm up and then dropped
See pictures at http://home.cogeco.ca/~photos
Anyway, vacuum seems OK.
I checked the resistance of the MAF - It was 4060 ohms at 8C which is a bit
high (should be 3420 to 3780 at 10C or 2299 to 2541 at 20C). Voltage to
MAF was also in range 5.02V. (should be 4.7-5.3v) (from Star Tek )
I tried to find the O2 sensor connection under the passenger side carpet -
even removed the plate in the footwell under the mat, but could not find the
green wire. Just two large bundles of wires passing through with no
connectors. Maybe you were thinking of the earlier W210?
Since I cleaned the MAF, the CE light has not come back on, but I have not
driven very much. One thing I wondered, is if the relay that actuates the
MAF cleaning cycle might be faulty - but I have no clue how to check this.