Monitors not ready for smog.

What is your question?

After driving 500 mules, warm up Catalyst & EGR Monitors not ready. Trying to figure out right cause. Cooling fan stays on with ignition, during driving & a few seconds after I stop the car. I disconnected noisy AC fan.I don't want it. Changed battery 6 months a go. Last time it was same situation and was not ready on both same monitors & after changing one Oxygen censor check engine light was gone and it passed the smog test. This time, I am wondering what should be fixed first. confused. Two months a go, there was a check engine light & it was gone by it self. There is no light now, Car runs excellent & perfect. Very confused....Thanks for your time.