Regarding these-

OXYGEN SENSOR MONITOR, OXYGEN HEATER SENSOR MONITOR, and EGR SYSTEM MONITOR

If there was a problem with them there would be a ses light set. There is no way that all or one of the above said items can be bad and it not throw a code but instead just say ''Not Ready''.

If it says ''Not Ready'' because there is a problem then there will be a code set also.