Hello, friendly Mercedes folk...Is there any way to isolate a bad injector other than the old "screwdriver-to-the-ear" trick? 259k, runs beautifully, but now and again at a tollbooth the idle drops.
Also, steering has been stiff lately. I don't mind stiff steering, but others have commented on it; every now and then, the steering colum groans lightly as it's turned. Should I change the power steering fluid?
Last question: there is a vent at the back of the well underneath the driver's armrest. The vent faces the back seat and blows absolutely frigid air all the time, whether the heat is on or off. I am in Boston in the winter--this may cost me friends!