An exhaust treatment system configured to treat exhaust gas generated by an internal combustion engine includes a reductant delivery system that injects a reductant solution into an exhaust gas. A selective catalyst reduction (SCR) device reacts with the reductant solution to reduce NOx from the exhaust gas. A control module is in electrical communication with the SCR device and the reductant delivery system. The control module determines at least one of an injection status of the reduction delivery system and a performance of the SCR device. The control module further determines at least one debounce time for delaying diagnosis of a NOx sensor based on at least one of the injection status and the performance of the SCR device.