×

Evaluating method for NO.sub.x eliminating catalyst, an evaluating apparatus therefor, and an efficiency controlling method therefor

  • US 5,693,877 A
  • Filed: 06/22/1994
  • Issued: 12/02/1997
  • Est. Priority Date: 06/22/1993
  • Status: Expired due to Fees
First Claim
Patent Images

1. An evaluating method for determining deterioration of a lean NOx catalyst installed in an exhaust gas system of an internal combustion engine for reducing NOx under a lean air-to-fuel ratio condition, comprising the steps of determining oxygen concentration upstream and downstream of the catalyst with a sensor when the engine is operated under the lean air-to-fuel ratio condition, andevaluating said catalyst by comparing a difference of the determined oxygen concentration upstream and downstream of said catalyst via the sensor.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×