Patent · US Expired

Catalytic converter monitoring using downstream oxygen sensor

US5159810A · kind A · utility

35Cited by
3References
11Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 26, 1991
Grant dateNov 3, 1992
Priority date
Expiry dateAug 26, 2011

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02T10/40
  • WIPO fieldEnvironmental technology
  • WIPO sectorChemistry

Abstract

An exhaust gas oxygen sensor downstream of a catalytic converter is used to control a closed loop air/fuel ratio control system. A measured limit cycle frequency at various engine speed/load conditions is compared to stored benchmark limit cycle frequencies as functions of engine speed/load conditions. If the measured frequency is higher, the catalytic converter is considered to be degraded.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.