What's the solution for Buick p0 172 system being too thick?

The main reason of Buick p0 172 system being too rich is that the fuel system voltage is high or the mixture is too rich. If the fuel system voltage is high, the solution is to clean the throttle. If the mixture is too rich, the solution is to replace the filter or oxygen sensor. The following is an introduction of Buick: 1. Buick is an automobile brand sold by General Motors in the United States, Canada and China. It is sold in North America, China, CIS countries and the Middle East. 2. Buick includes many well-known models: Buick Excelle, Buick Hideo, Buick Lang Wei, Buick Lang Yue, Buick Regal, Buick LaCrosse, Buick Angkor GX, Buick Angkor S, Buick Angkor flagship store, Buick GL6, Buick GL8 Land Business Class, GL8-ES Land Zun, pure electric micro-blue VELITE6 and high-end sub-brand Avenir.