CLK500 TWINS

To those who have been helping me with this car, a reminder and to those who are just reading:
I had an issue with flat battery, no charging - solved with new alternator and my guy chased down a huge draw from aftermarket TV's that were installed (not by me). Then with power problem solved, I still had the rough running problem with the code indicating car was running too rich at idle. Replaced the maf with a genuine bosch and Idle is smooth with an intermittent vibaration. Acceleration is 4 times more responsive. Only things Im noticing are: a sometimes slight and other times obnoxious virbation in reverse and it doesn't start right up with a turn of the key. It starts, everytime, but I feel like it takes it a couple of seconds to catch as opposed to turn key-vroom. CEL light still on, had a P0100 Maf circuit a code (ran at an auto parts store). Its been about 2 weeks and a blizzard later. Car runs fine in comparison to what it was doing, but we can't seem to get rid of this ding dang light.

Was finally able to get it back to my guy today and he pulled the P2004 code with the Maf hot film sensor description. He looked for the butterfly piece on the intake manifold but it's not throwing an intake manifold actuator desription. We're at a loss.

CLK500 TWINS

Side bar: Can anyone tell me what these plugs are and where they are supposed to connect to. I assumed the abc system as the suspension has been converted, but the bilateral ones coming off the engine block dont make much sense to be part of the disconnected abc system One on both sides. Coming off engine block
One on both sides, near strut housing. Probable ABC?