Have you done any electrical work lately? I fried my O2's once while I was wiring an A/F ratio gauge. Anyway, I got primary and secondary O2 codes, as well as the heater circuit codes. I replaced both my O2's with universal pieces that were spliced on. The primary O2(EFI Systems) worked very well, and my primary O2 codes went away. The secondary(Bosch), however, didn't work all that great for some reason. All my codes went away, excep for the secondary O2 heater one, and now that I think about it, I probably got the heater circuit wires reversed when I spliced the harness on. I ran like that for about two years with no real problems, so driving like that shouldn't be too bad temporarily. You should try to handle it at your earliest convenience, though, since the primary O2 is very important. My secondary O2 codes went away completely after I swapped in an OEM O2, and after two years of the CEL staring me in the face, I was once again code-free.