Folks, I have a beautiful 2005 SRT6 coupe that runs like a champ with 86k miles. Possibly the smoothest n quickest car I have ever owned, and I have owned many. I also have been fighting the P0410 issue. Here is what I have done:
1) I started getting the P0410 code. RCM rebuilt by tighed1, new relays and horny mod. After a I put in the rebuilt RCM, the 40A fuse blew as soon as I turned on the car from a cold start.
2) Replaced the 40A fuse on the RCM and with a voltmeter measured 14V or so on the connector going to the secondary air pump. So I figure my air pump needs replacement.
3) Replaced the air pump. Emission Smog Air Pump For Mercedes-Benz SLK32 AMG V6 3.2L S63 CL63 AMG V8 6.3L | eBay. K-Parts. Emission Smog Air Pump For Mercedes-Benz SLK32 AMG V6 3.2L S63 CL63 AMG V8 6.3L. Fit like a glove.
4) Now when I start the car cold I hear the air pump turn on for the first 30 seconds or so. I figure I fixed it, but wrong. After a day of driving, the P0410 comes back. I clear codes. Still comes back after a few days.
5) I replaced the blue air check valve from AutohausAB, (0021408460, Vacuum Check Valve). I clear codes. The air flow from the blue check valve seems fine. I follow the air line to the top of the blower and it also seems clear (not clogged).
6) After a few days of driving, I get the P0410.

What could it be? The I took picture if my next suspect, below. It is a small canister from where the the blue check valve gets the air flow.