An exhaust system includes a light-off catalyst, an exhaust system component, and at least one H2O trap. The exhaust system component is upstream from the light-off catalyst and includes catalyst material, the catalyst material configured to store hydrocarbons during a period when the light-off catalyst is warming up to a light-off temperature. The at least one H2O trap is at or upstream from the exhaust system component and is configured to perform H2O adsorption and desorption to increase a length of time for the exhaust system component to reach a hydrocarbon release temperature and prevent the exhaust system component from reaching the hydrocarbon release temperature prior to the light-off catalyst reaching the light-off temperature.