14mo old was hospitalized for pneumonia in both lungs. fever broke &o2 staying steady @91 so discharged. how long til he starts acting/feeling well?

Pediatric pneumonia: This depends upon the causative agent of the pneumonia, the treatment used and the underlying health of the baby. Hopefully, like most infants, he will bounce back fairly quickly and begin acting his normal self within a week or so. Best wishes.

Estimate difficult: It really depends on a number of factors. Observe the baby closely for increased respiratory effort, change in coloration, sweating and other signs of distress. As the lung heals you should definitely see improvement over the next two weeks, but it is difficult to estimate.