摘要 |
An apparatus, system, and method are disclosed for real-time diagnosis of a NOx-adsorption catalyst (NAC). The method includes verifying that a NAC temperature exceeds a threshold, determining that the NAC is in a steady-state operating condition, and surveying a first oxygen sensor upstream of the NAC and a second oxygen sensor downstream of the NAC. The method further includes calculating a lambda difference between the first and second oxygen sensors, and interpreting a NAC regeneration indicator. The method further includes determining a lean-to-rich transition and a rich-to-lean transition area based on the lambda difference and the regeneration indicator. The method concludes with setting a NAC function indicator according to the lean-to-rich transition area and the rich-to-lean transition area. |