Methods, systems, and vehicles are provided for estimating nitrogen oxide values for vehicles. In accordance with one embodiment, a system includes a memory and a processor. The memory is configured to store one or more kinetic models pertaining to a propulsion system for a vehicle. The processor is configured to at least facilitate obtaining a nitrogen value pertaining to a selective catalytic reduction (SCR) unit of the propulsion system, obtaining an initial nitrogen oxide measurement via a nitrogen oxide sensor of the propulsion system, using the nitrogen value as an input for the one or more kinetic models pertaining to the propulsion system, generating a kinetic model output from the one or more kinetic models, and estimating an updated value for the initial nitrogen oxide measurement based on the kinetic model output.