We used a box model to study the sensitivity of ozone production by different precursors within the Houston metro area during NASA's DISCOVER-AQ air quality field mission in 2013. We constrained the box model to observations from the campaign and to a 3-D model for species that were not measured. By focusing our analysis on different locations and times of day within the metro area, we were able to suggest which ozone precursors, if controlled, would have the greatest impact on ozone reduction.