Agree with Doc on this one. Bought a so called "brand new" one off ebay. It was a complete diaster. It was not original and not new. Looks like a refurb with off-brand casing. My 2001 ML320 ran worse with it than my original one. Fortunately, took action quickly with Paypal and was able to re-coup some of my money (I sent the unit back to the seller). I learned my lesson on buying parts.

I spent the money and get a genuine Bosch OEM from my dealer. The car runs much better now. I know the dealer and MB pricing on MAF is a ripoff. Driving a Benz means you have to put up with many of these ripoffs. I could have saved $100 by ordering from Duvall had I known them then. Anyway, don't settle on anything other than OEM for these electronic sensors. I can see using some not so critical mechanical parts from non-oem. But MAF is not one of them.