lexsoarer400

i'm getting codes 25 and 26, too rich and too lean exhaust, i did some searches and found out it was probably the O2 sensors. But my check engine light only comes on for the first 5-10 min when driving and i feel/hear the car get a lot better once it has warmed up. I also read something that the O2 sensors are/should not send any information until they are warm. It makes me think the O2 sensors are alright and working right once they are warm but for some reason sending information before they should? I don't know too much about this stuff just trying to put what i know/read together, so i'm probably way off but any help would be great. Thanks