I think that it is the same device. This check/PCV valve is immediately under the intake manifold and thus very difficult to see and access. In another website, it is recommended to remove the intake manifold which appears to be not that big a task. According to the Bentley manual, you need to remove the fuel rail and injectors from the manifold, move to the side, and then the manifold can be removed. You need to replace the two manifold gaskets (about $12 each at the local dealer) when you are re-installing.

I hope that there is someone here who has done this to provide some guidance to this work. This issue seems to be relatively common to the C230K and CLK models.

Cheers,
Paul

__________________
1989 300E
1999 C230 Kompressor
2005 Toyota Highlander AWD

Also owned:
1964 Chevrolet Impala (first car)
1972 Fiat 124 Sport Spider (first sports car)
1976 VW Scirocco (first new car)
1970 Pontiac Parisienne (epitome of bland)
1980 VW Scirocco (last new car)
1953 GMC 6x6 (amazingly well engineered)
1967 Austin Healey 3000
1987 F150 4x4
1978 F150
1987 VW Jetta
1992 Toyota Previa AWD
2003 Toyota Sienna
2001 Nissan Pathfinder 4WD
1949 John Deere Model M