I had the same codes in my 97 S500 and I changed the Air Mass Meter and that fixed the problem. Also, the engine seemed to have a little more snap after the change. As you probably know, these codes represent an exceedence has been recorded in the ECM's ability to "adapt" to a rich or lean condition. As I understand it, either a bad AMM on the intake side or O2 sensors on the exhaust side can lead to adaptation values to be exceeded. If you only had one cylinder bank throwing you a code, it could be either the AMM or an O2 sensor but since you have both banks throwing you the same code at the same time, chances are great that it's your AMM since it would be quite a coincidence that more than one O2 sensor would fail at the same time. This is as far as my rice paper thin knowledge goes regarding adaptation values. All I can say is that I replaced mine and all my problems went away!

If you want to know more about adapation values than your local MB tech, read this: http://benzworld.org/forums/forums/thread-view.asp?tid=1203330&start=1&fid=13 Look about halfway down the thread on the first page. The article is titled "Adapation Values" (I think it originaly comes from Stevebfl- so thanks Steve)

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Paul Hansen

1997 S500 (100,000mi)