Experimental study on the emission influence of the fuel system faults for light-duty vehicle

The fuel system is a very important system in light-duty vehicles. The faults of the system will cause serious deterioration of vehicle emissions and other performance. In order to study the influence of different types of faults on emissions, this paper studies the faults of several OBDII vehicles. The results show that: the fault of rich mixture in fuel system will increase the emissions of CO and NMHC by 3-5 times and the emissions of NOx by 1-2 times; the fault of lean mixture in fuel system will increase the emissions of NOx by 4-5 times and the emissions of CO and NMHC by 0.7-2.5 times; there are two kinds of imbalance faults, one is imbalance lean and the other is imbalance rich. Imbalance lean mainly causes NOx deterioration, which is increased by 7.5 times. Imbalance rich mainly causes CO and NMHC emissions deterioration, which is increased by about 3 times. There are many kinds of faults in the fuel system which cause serious deterioration of emissions. It is necessary to focus on monitoring the faults of the fuel system.