Idle Air Mixture- 1980 SEL

[DasCar]

I have high idle on a 1980 SEL (gasser) after the engine is warm.  In reading the manual, it describes a list of changes for the CIS A system that includes this:

MB 07.3-500  "...The idle air mixture is no longer controlled as before by way of a CO measuring instrument, but by way of the on-off ratio of lambda control"

I ran through the list of items to check for fuel injection for high idle (ignition, fuel pressure, etc.) and all is well.  So can I now just crank down the idle screw and not worry about the idle air mixture screw and CO output?  Anything else I should be checking? O2 sensor?