Systems and methods for detecting and validating a leak in a fuel cell system are presented. In certain embodiments, various fuel cell stack set points may be adjusted such that adequate H2 flow data may be obtained to identify and validate an H2 leak and/or a location of such a leak. In some embodiments, H2 flow data may be obtained by adjusting certain fuel cell system operating parameters under a variety of operating conditions and/or modes and measuring flow data under such various operational conditions.