NEED quick help with code

[sckby5]

So I need to pass emissions here in chicago, illinois within the next two weeks or my plates get suspended. Its a 96 chevy beretta and the code i get is this....
PO138 HO2s circuit high voltage sensor 2
What is causing this and how can i fix it, the 02 sensors are all new and it still reads this code, and the code was cleared after putting in new sensors, WTF! need help quick, thanks guys

[maxwedge]

You need to get a good scanner on this and look at the voltages generated by the sensor, also check the wiring in the circuit back to the pcm, if possible use a scanner such as a Snap On mtg 2500 which can graph that sensor and also has a troubleshooting function for tracing down the root cause of the code, no quick fix here.