Tested the Throttle switch and air flow sensor potentiometer per Dan's page

Both tests were pretty much around ~.5%

So the Potentiometer is working fine. I tried to get it to go into closed loop by going CCW and CW till the car was barely running but i still couldn't find that sweet spot. Duty cycle stuck at 82% and fluctuating on the decimal figures.

I tested the O2 sensor per Oxygen Sensor / Lambda Sensor Voltage Testing - Benzworld.org - Mercedes-Benz Discussion Forum and all the values I got were around 4.5-7.5V. I had set the Multimeter to hundredths too.

Also there seems to be a short at my O2 sensor heater because the interior lights flicker when I move that connection around. Is that normal?

Anyways I'm buying a new O2 sensor today and see if it makes a difference.

Current at pin #5 was 12.7V and the voltage at battery was 13.6 - I'm guessing my OVP is in good shape.

Thanks everyone for all the help
Visal