These threads have been extremely helpful in diagnosing and repairing a number of issues w/ my ML so I thought I should contribute also. My MAF went out, I found a reasonably priced (~$200) replacement at NAPA and bought it. To date, I have gone through three of the remanufactured Bosch units, they work for a week or two, then the light comes back on and I get the two MAF malfunction codes....I have now been through three of them, at least my NAPA store honors the lifetime warranty and replaces them free w/o giving me grief. Still, I'm consideing plunking down my $300 for a new one just to avoid the headache.