I have a 300CE with M103. I just swapped my cylinder head with a Brabus one that I got from one of the members here. After installation, I sent my car to a Mercedes Specialist to get the engine tuned up. The Mercedes Specialisit told me I needed to replace the "Charcoal Filter" to smooth out the idling. Any truth in this?

BTW, where's the Charcoal Filter located?

Rgds