Phil here at Mercedesshop can probably get the wiring harnesses for a good price. And Caliber Motors in Anaheim Hills has discounted prices too. And some dealers will replace it as part of "good will" for nothing at all, apparently.

For further diagnosis of the CMP sensor and oxygen sensor, I recommend first checking four systems for codes: the left and right fuel injection control modules and the left and right ignition control modules. These are sockets 5, 4, 18, and 17 of your diagnostic connector, respectively.