Chemical reactions of ground-state species strongly govern the formation of excited-state species, including OH* and CH*, which are commonly used to determine ignition delay times of fuels. With well-characterized chemiluminescence rates embedded in chemical kinetics mechanisms, time histories of excited-state species can aid in identifying influential ground-state reactions which are important to processes such as ignition delay time. Placing emphasis on the high-temperature regime, improvements were made to a detailed chemical kinetics mechanism of n-nonane oxidation developed previously by the authors. Using characteristic features of OH* time histories measured in shock-tube experiments as a metric, detailed model analyses were performed over a broad range of conditions: T>1100 K, 1.5