Sensor monitoring methods and systems

1. A method of monitoring a sensor of an exhaust system, comprising:

evaluating humidity of air entering the exhaust system; and

monitoring operation of a sensor in the exhaust system based on the humidity,

wherein the evaluating comprises evaluating whether the humidity is within a predetermined range, and when the humidity is within the predetermined range, enabling the monitoring the operation of the sensor.

2. The method of claim 1 , wherein the sensor is a NOx sensor.

3. The method of claim 1 , wherein when the humidity is outside of the predetermined range, disabling the monitoring the operation of the sensor.

4. The method of claim 3 , further comprising setting a value of a diagnostic code based on the monitoring.

5. A method of monitoring a sensor of an exhaust system, comprising:

evaluating humidity of air entering the exhaust system;

monitoring operation of a sensor in the exhaust system based on the humidity;

determining a correction factor based on the humidity; and

applying the correction factor to a threshold,

wherein the monitoring the operation of the sensor is based on the threshold.

6. The method of claim 5 , further comprising evaluating whether the humidity is within a predetermined range, and wherein when the humidity is within the predetermined range, enabling the determining the correction factor.

7. The method of claim 6 , further comprising evaluating whether the humidity is within a predetermined range, and wherein when the humidity is outside the predetermined range, disabling the determining the correction factor.

8. A system for monitoring a sensor of an exhaust system, comprising:

a first module that evaluates humidity of air entering the exhaust system; and

a second module that monitors operation of a sensor in the exhaust system based on the humidity,

wherein the first module evaluates whether the humidity is within a predetermined range, and when the humidity is within the predetermined range, the second module enables the monitoring the operation of the sensor.

9. The system of claim 8 , wherein when the humidity is outside of the predetermined range, the second module disables the monitoring the operation of the sensor.

10. The system of claim 9 , further comprising a third module that sets a value of a diagnostic code based on the monitoring and that generates a message including the diagnostic code.

11. A system for monitoring a sensor of an exhaust system, comprising:

a first module that evaluates humidity of air entering the exhaust system;

a second module that monitors operation of a sensor in the exhaust system based on the humidity; and

a third module that determines a correction factor based on the humidity, and that applies the correction factor to a threshold,

wherein the second module monitors the operation of the sensor based on the threshold.

12. The system of claim 11 , wherein the sensor is a NOx sensor.

13. The system of claim 11 , wherein the third module evaluates whether the humidity is within a predetermined range, and when the humidity is within the predetermined range, the third module determines the correction factor.

14. The system of claim 13 , wherein the third module evaluates whether the humidity is within a predetermined range, and when the humidity is outside the predetermined range, the third module does not determine the correction factor.