A model hydrocarbon trap material consisting of palladium promoted zeolite beta on a monolith core was studied with a multicomponent hydrocarbon feed. Dodecane and ethylene adsorption, followed by temperature programmed oxidation (TPO), was used in the presence of CO in wet and dry conditions to study the impact of various species on hydrocarbon storage, oxidation, and desorption. Low temperature adsorption experiments were used to quantify hydrocarbon storage capacity, while temperature programmed desorption (TPD) and TPO studies were used to investigate both oxidation and desorption of the various hydrocarbon species. The low temperature adsorption experiments suggest a moderate impact of water on dodecane uptake as dry experiments adsorbed more dodecane overall than those under wet conditions. Additionally, the presence of CO and ethylene also impaired dodecane uptake. TPD studies indicated a coupled relationship between hydrocarbon oxidation light-off and desorption. By varying the composition of the feed, specifically via the inclusion of CO or ethylene, dodecane oxidation light-off was delayed, which actually increased the overall hydrocarbon trap efficiency.