1999 S420 - MAF replacement
 

I have been having difficulty finding a 1999 s420's MAF that is reasonable priced. Nor, have I been able to find an insert, which I would prefer. I am able to find a 2000 s430 MAF that is new and reasonably priced. The insert appears to fit within the same slot on the 1999 throttlebody, but the connecting harness of the 2000 is different from the 1999. :idea3:I was wondering whether there is a crossover wiring schematic(s) that would allow the use of the 2000 in place of the 1999 (complete setup). The air collected by both engines, the 420 and 430, should be the same. Any ideas??!!

just poking around the net, I found one for yours for around $355.
Thats about what I paid for mine on my E

Thats interesting that they are so much (Phil's is $500ish), my 99 E300 is only $200 (Phil).

I think a lot of folks have had troubles with the inserts going bad quickly.

Have you tried cleaning yours with CRC MAF/AMM spray cleaner? Sometimes it works.

http://catalog.worldpac.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=285002WZV2850030LO&year=1999&make=MB&model=S-420-002&category=B&part=Air+Mass+Meter

Their you go, thats what they cost. S class Mercedes are very expensive cars to own.