A system for detecting an analyte gas including a system housing having an inlet system, an electrochemical gas sensor within the housing and in fluid connection with the inlet system, the electrochemical sensor including a working electrode responsive to the analyte gas, and a control system in electrical connection with the working electrode. The control system is operative to bias the working electrode at a first potential at which the electrochemical gas sensor is responsive to the analyte gas and operative to bias the working electrode at a second potential, different from the first potential, at which the electrochemical gas sensor is sensitive to a driving force created in the vicinity of the inlet system to test at least one transport path of the system.