I have a 93 300e 3.2 HFM here with the idle fluctuating like it has an air leak. I can not find one. I have retrieved the following faults:
012 -Engine idle speed contact, air mass too large
013 -Idle contact switch, bad contact

I had just replaced the wiring harness, these faults came up with another air mass fault, I checked the afm readings at an idle an the flow rate kept dropping off to zero. I replaced the air meter, now the air flow shows steady, but the idle still flucuates, accompanied by a raunchy exhaust odor.
Is the "idle switch" part of the throttle unit in this application? The manuals I'm using (Mitchell) does not go into much detail on where to go next. I would much rather fix this with some friendly advise from those who have delt with this before than to chase my tail for days.
Thanks, Dan