I did mine a month after purchasing w210 in 2005. I had never looked under the hood of a w210 before. If you have some mechanical skills its not difficult. I was very fortunate that they all came out fairly easy. I did a search here and printed the instructions. While I had the manifold off, I cleaned it, the EGR, and the intake flaps. All went smooth, however I did end up breaking a wire to one of the transducers and it needed a trip to dealer to diagnose.

__________________
Dennis
2006 E320 CDI Black/Black Leather. Nav, HTD Seats HK stereo 32000 miles.
2000 VW Passat 1.8t 300,000 miles as of Dec 09, 2009 original owner
1997 E300d Silver 300,000 miles As of Jan 05, 2010
3rd owner SOLD