In the exhaust between the engine and the catalytic converter.
There is a total of 4 oxygen sensors the 2 upstream sensors are located right below the exhaust manifold flanges and above the upstream catalytic converter.The 2 downstream sensors is located in the exhaust pipe,right behind the upstream catalyst,and ahead of the main catalyst.
All O2 sensors are threaded into the exhaust system at various points. Upstream O2 sensors are located before the catalytic converter(s) and downstream O2 sensors are located after the catalytic converter(s).
upstream 02 sensor located right above exhaust manifold gasket downstream located right in front of catallytic converter
Upstream will be the closest to the engine, and are used to sense the air/fuel ratio and tell the computer how much fuel to inject. Downstream sensors are used to verify the upstream sensors and convertors are functioning correctly, so they are located after the convertors.
There are 2 or 3 oxygen sensors in your exhaust. "Upstream" sensors are located between the exhaust manifolds (headers) and the catalytic converter (usually located on the mid-pipe); "downstream" sensors are located after the catalytic converters. On V6 Mustangs there can either be one or two upstream sensors and usually only one downstream sensor.
There are two upstream O2 sensors 4.0L V6 Upstream & Downstream Sensor Locations * Both upstream sensors are screwed into the exhaust pipe right below the exhaust manifold flanges * Both downstream sensors are located in the catalytic converters 4.6L V8 Upstream & Downstream Sensor Locations * The left upstream sensor is screwed into the exhaust manifold right above the manifold flange and the right upstream sensor is screwed into the exhaust pipe right below the exhaust manifold flange * Both downstream sensors are located in the catalytic converters
before and after catalytic converter.
The 1996-2001 Elantra's have two sensors the upstream and downstream the upstream sensor is located the exhaust manifold and the downstream is located behind the catalytic converter.
There are 2 oxygen sensors one upstream and one down stream. Both oxygen sensors are located underneath the van. The down stream oxygen sensor is located behind the cataylic converter near the cross pipe and the upstream oxygen sensor is located in front of the cataylic converter in plain sight. They look like spark plugs with either 8", 12", or 14" wires attached to them. The upstream oxygen sensors is easily located underneath the vechicle to the front. The downstream oxygen sensor is not the one lcoated on or close to the cataylic converter.
Assuming we are talking O2 sensors, the downstream O2 sensors left and right are the same. The upstream O2 sensor left side is left side upstream only. Upstream right side fits both left and right sides upstream only. The difference is the length of the wires for the upstream sensors.
the upstream O2 sensors, are located on the top of the exhaust manifolds. they are sitting right there in the open where you can see them.
The oxygen sensors are screwed into the exhaust on the rear of the engine. The upstream is before the catalytic converter, the downstream is after.