I just drove home from a friend's place. The car idled badly, surging between 400 and 1000 rpm. About 1/2 mile from home it smoothened out. Seems to run fine although it may be in limp-mode. I am not sure how to tell, the car is new to me, do not have enough experience regarding expected performance.
On Friday I called MB Canada regarding the wiring harness issue. The warranty department assured me that in Canada the 124 model did not have those problems, it may be strictly a US experience. His explanation was that because of the different pollution control equipment the harness may be different between the US and Canadian models.