METHODS AND SYSTEMS FOR AMMONIA SLIP DETECTION

摘要

Various systems and methods are described for detecting ammonia slip. In one example method, an amount of exhaust gas recirculation is reduced when output from an exhaust gas sensor indicates an increase in nitrogen oxide above a threshold amount. When the sensor output increases above a second threshold while the exhaust gas recirculation is reduced, the sensor output is allocated to nitrogen oxide; and when the sensor output does not increase above a second threshold while the exhaust gas recirculation is reduced, the sensor output is allocated to ammonia.