This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Detection of Catalyst Performance Loss Using On-Board Diagnostics
Annotation ability available
Sector:
Language:
English
Abstract
Proof-of-concept testing was conducted to evaluate the ability to identify serious losses in catalyst efficiency with a dual oxygen sensor method. The dual oxygen sensor method involves a comparison between the signal from a pre-catalyst oxygen sensor to that from a post-catalyst sensor. Testing was conducted on a dynamometer test stand in an open-loop mode under steady-state conditions. Four matched catalysts and two deteriorated in-use catalysts were tested. The matched catalysts were identical in all physical characteristics, but with varying efficiencies. The operating air-fuel ratio was dynamically varied, and the test matrix included amplitude variations of the air-fuel ratio from 0.5% to 7% above and below the stoichiometric point, oscillating at three frequencies. Results from this proof-of-concept testing show measurable differences in the pre- and post-oxygen sensor signals between catalysts with good and poor conversion efficiencies. These laboratory tests suggest that the dual oxygen sensor concept appears to be a feasible method to detect gross changes in catalyst activity with an On-Board Diagnostic system.
Recommended Content
Authors
Citation
Clemmens, W., Sabourin, M., and Rao, T., "Detection of Catalyst Performance Loss Using On-Board Diagnostics," SAE Technical Paper 900062, 1990, https://doi.org/10.4271/900062.Also In
References
- Gandhi H.S. Piken A.G. Shelef M. Delosh R.G. SAE Paper No. 760201 (in SP-403) Laboratory Evaluation of Three-Way Catalysts 1976
- Matsunaga S. Yokota K. Muraki H. Fujitani Y. SAE Paper No. 872098 Improvement of Engine Emissions Over Three-Way Catalyst by the Periodic Operations 1987
- Meitzler A.H. SAE Paper No. 800019 Application of Exhaust-Gas-Oxygen Sensors to the Study of Storage Effects in Automotive Three-Way Catalysts 1980