You really need to have this properly diagnosed in a very methodological manner.
Just getting codes and throwing parts at it is very costly and unproductive.
We were getting similar problems and traced it to an intermittant O2 sensor connector.
Also, my tech uses an electronic cleaner that flashes quickly and is safe for sensors, to clean the MAS sensor.
A good read on how other system faults can cause a fault code is here:
A good OBDII scanner should be able to read the "freeze frame" data which tells you things like engine speed; temperature; etc., when the fault happenned.
It should be repeatable, so reset, and borrow the OBDII scanner and drive around until you get the check engine light.
1988 360TE AMG (w/1995 C36 engine, tranny, computers)