Air-Fuel Control to Reduce Emissions I. Engine-Emissions Relationships

Relationships between the oxidants and the unburned fuels in the exhaust gas provide effective measures of emission system performance. These include the mean deviation from stoichiometry, air-fuel distribution, and catalyst storage effects all under dynamic conditions. Basic concepts of the interaction of air-fuel ratio, exhaust gas composition and catalyst performance are reviewed, further developed and simplified for use by the development engineer in evaluating system performance.