How to try the oxygen sensor

Hello friends of this forum I have a volswagen goal that the oxygen sensor this evil tells me the mechanic because I started the fuel ...... and as I can try the sensor it is 4 cables .....

You click on the black cable of the four that have two targets and the gray with a polyymore has to range the tension between 0.50 and 0.900 MV. Changing the value more less every second according to the accelerate and the vehicle hot.
But I would begin to disconnect the battery for a few minutes and provaria to see how the corrects of the correct COs are given below 0.30 and Landa below 1030.
or buy what you spend.

Ok friend will I try to try that way
the black color is signal ??? What has to oscillate right ???