Mercedes Benz Workshop Service and Repair Manuals

Oxygen Sensor: Electrical Specifications

Oxygen Sensor Heater Resistance................................................................................................................................................3 ohms (cold) 13 ohms (hot)
Oxygen Sensor Operating Voltage (engine running)...........................................................................................................................................0.4 - 1.0 volts
Oxygen Sensor Heating Element current draw.........................................................................................................................................................0.5 - 1.3 A

Tune-up Specifications

Firing Order.....................................................................................................................................................................................................1-5-4-8-6-3-7-2
Idle Speed....................................................................................................................................................................................................500-600 RPM [1] 
Timing............................................................................................................................................................................................................5 ±2° BTDC [2] 
Air/fuel Mixture....................................................................................................................................................................................Readout oscillating [3]

[1] Automatic Transmission in Drive
[2] Reference figure at cranking speed only, not adjustable
[3] At Diagnostic socket, with on/off ratio tester, and O2 sensor connected