O2 Sensor: Description

The upstream O2 sensors are in the exhaust system in the exhaust manifold collertor area before the upstream catalytic convertor (Fig 1).

Fig 1: Identifying 2/1, 2/2, O2 Sensors

Courtesy of DAIMLERCHRYSLER CORP.

The downstream O2 sensors are in the exhaust system in between the catalytic convertors (Fig 1).