That is the oxygen sensor screwed into the downstream side of the catalytic converter.That is the oxygen sensor screwed into the downstream side of the catalytic converter.
4 sensors total. 2 upstream on either side of exhaust manifold, 1 left side downstream, 1 right side downstream.
Downstream O2s are on the outlet side of the catalytic converter(s).
On a Ford Expedition : Bank 1 , Sensor 2 ( downstream ) is the sensor for the passenger side of the engine Bank 2 , Sensor 2 ( downstream ) is the sensor for the drivers side of the engine So in short the answer is from the ( drivers seat )
From underneath car there about 2' apart on either side of converter. Upstream is much harder then the downstream which is easy
It is after the catalytic onverter on the same side of the engine as cylinder #1.
When oil flows through an orifice, the pressure on the upstream side (before the orifice) is typically higher than the pressure on the downstream side (after the orifice). This pressure difference is necessary to overcome the resistance to flow caused by the orifice's size and shape. As oil passes through the orifice, it accelerates, resulting in a decrease in pressure on the downstream side according to Bernoulli's principle. Therefore, the pressure on the upstream side will always be greater than the pressure on the downstream side during flow.
ther are 2 oxygen sensors, an upstream and a downstream . The upstream is on driver side of engine exhaust and the downstream is back of catylitic converter agin on exhaust pipe.
Upstream is an O2 sensor located between the engine and the catalytic converter. Downstream is one located behind the converter.
drivers side of engine , downstream from catalytic converter
drivers side of engine , after catalytic converter ( downstream )
Bank 1 = Cylinder 1/Drivers Side Bank 1 Sensor 1 = Upstream (before cat) Drivers Side Bank 1 Sensor 2 = Downstream (after cat) Drivers Side Bank 2 Sensor 1 = Upstream (before cat) Pass Side Bank 2 Sensor 2 = Downstream (after cat) Pass Side