Since the fuel system is running *RICH* that means that the return voltage fron air mass sensor is too high!! OHMs law says that resistance can lower voltage, so yes there are other repairs! if you can figure out the return voltage from your air mass sensor to the ECU! The DM has to see the LH-ECU at that limit(.85) to turn the check engine lamp on.
CLEANING the throttle body DOES help with LOW idle speeds.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator