O2 Sensor: Description

Fig 1: Identifying O2 Sensor Components

Courtesy of DAIMLERCHRYSLER CORP.

1 - ELECTRICAL CONNECTION

2 - SENSOR HOUSING

3 - ACTIVE CERAMIC PROBE BODY

4 - MATING SURFACE

5 - HEATING ELEMENT

6 - PROTECTIVE TUBE

7 - INNER, OPEN COMBUSTION CHAMBER

8 - ELECTRODE (OUTER)

9 - ELECTRODE (INNER)

The Oxygen Sensors (O2S) are attached to, and protrude into the vehicle exhaust system. The vehicle uses a total of 4 sensors; 2 upstream (referred to as 1/1 and 2/1) and 2 downstream (referred to as 1/2 and 2/2). The right upstream sensor (1/1) is located in the right exhaust pipe just before the mini-catalytic converter. The left upstream sensor (2/1) is located in the left exhaust pipe just before the mini-catalytic converter. The right downstream sensor (1/2) is located in the right exhaust downpipe just after the mini-catalytic converter, and before the main catalytic converter. The left downstream sensor (2/2) is located in the left exhaust downpipe just after the mini-catalytic converter, and before the main catalytic converter.