I have read about this problem a few times on the German M-B forums.
Seems the only cure is to replace the parts you have mentioned.
Once the camshaft sensor develops a leak, there is a "wicking " action, that allows oil to migrate right up and into the ECU.
I would try spraying some Brake Cleaner ( it will almost instantly evaporate & carry the oil away ) into all accessible places & see what happens.

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2007 C 230 Sport.