Catalytic converter diagnostic
US5431011A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 14, 1993 |
| Grant date | Jul 11, 1995 |
| Priority date | — |
| Expiry date | Dec 14, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A diagnostic for an internal combustion engine exhaust gas treatment means includes a series of enabling conditions for modelling temperature and operational stability of the treatment means and includes first and second stage tests alternately applied on an engine air/fuel ratio cycle-by-cycle basis in accord with the diagnosed performance of the treatment means using post-converter oxygen sensor information. When the treatment means performance is diagnosed as being degraded close to a failed condition, the first stage is disabled and the more statistically rigorous second stage is activated to closely scrutinize converter performance using a two phase approach for false alarm protection.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.