To test the robustness of the pressure-dependent results for all three peroxy radicals studied, various sensitivity studies were conducted. To investigate sensitivity to barrier hights, one important barrier in each network was adjusted. Figure of the ESI † shows the major stabilized product branching ratios, similar to those shown in Figures , and 11, for the updated barrier heights. With the αAdductFromRO2 barrier height increased 13 kJ/mol, the α-network still forms only HO 2 and isobutanal. With a 10 kJ/mol barrier increase to β-γHO2elimFromRO2 corresponding to that of Sun et al., the branching ratio of the Waddington pathway increased noticeably. At higher temperatures, the other HO 2 elimination pathway, forming ibutenol, was found to dominate. Decreasing the barrier height of γH2OForm by 6 kJ/mol (to the value given by Welz et al.) shifts the system toward that pathway, but to a smaller extent than seen in the β-network. Overall, while some changes resulted from changing barrier heights, there were no significant shifts in product distributions, indicating that the differences in barriers in this work and that of others are not expected to significantly change predicted product distributions.