Well I have all four O2 sensors replaced and the Check engine Light is still coming on after reset. Code shows Sensor 2 Bank 2. Is this the rear sensor on the drivers side ? What else would show that code ?
Mabey a bad cat, however, I think that there is a seperate code for that. I would not worry to much about the O2 sesnors past the cat, they just check for emissions, the first 2 regulate fuel consumption. I have my passanger side throwing a code, PO161 or PO135. It has been like that for about 4 months now with out a problem. Now the diver side pre-cat sensor just went so since I am down there I will be replacing the other sensor. If I may ask why did you have all 4 replaced? Was it all done at the same time?