Code P0172 came up in my 2010 Chevy Malibu. The dealer charged me $100 to troubleshoot the code. I was told that all the sensors were good and to run the gas tank low and fill up with high-octane gas.
Neither black tape nor a magic marker is the solution when your car or truck's check-engine light comes on. When the light, which is shaped like the outline of an engine, illuminates, do not panic!