I took the 400E out for another long drive today and it ran perfect and did not exhibit the power loss problem that it still did yesterday (after I had replaced the harness). I hate this intermittent stuff. You can bet it will run fine until I take a interested buyer out in it and then it will act up again. It has done this to me three times now and scared the buyer off each time. I have been all over the top end of this engine and can find nothing. I checked the coolant temp sensor at different temps and the resistance reading is right on. I was thinking of removing the mass flow/throttle body (or whatever Mercedes calls that thing) and inspecting it closely, but I can't see how to get it out of there. Are there any relays I should be looking at? HELP!

Garry