is this green wire for the o2 sensor?

 

That would be a temperature sensor. FYI, that's not a good way to hook up two sensors because the water won't really circulate accross the sensors. This is assuming that the other thing connected at the bottom is another sensor.

 

i am looking for the o2 sensor wire, if anyone could help me locate it. i wanted to put in a air/fuel gauge

 

The O2 sensor will be screwed into the exhaust system somewhere close to the engine. Mine is on the driver's side.

 

thanks

 

Driver's side, near the exhaust manifold. It looks like a spark plug on one end. Follow the wire, which should have a plastic housing on the end.