Q: 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 ...

Onboard diagnostics (OBD) systems have been around since the 1980s and were developed to help limit harmful automotive exhaust emissions. Between 1988 and 1995, U.S.-built vehicles came with what's ...