The Imbalance Evaluation between Cylinders of Air-Fuel Ratio Sensor Sensitivity in Exhaust Flow Simulation

Abstract

OBD2 Regulations in the US require that OBD2 System should detect exceed FTP Emissions Standards caused by Air-Fuel Ratio Cylinder Imbalance. In order to detect Air-Fuel Ratio Cylinder Imbalance, each cylinder's exhaust gas should make sensor reacts. Therefore, the method of evaluating a function to detect the Air-Fuel Ratio Cylinder Imbalance by using CFD was constructed. Comparing the simulation results with the experiential results, it has been found that this evaluation method can reproduce the influence degree of each cylinder gas.