In the early years of electronically controlled cars -- through the 1970s and 1980s -- technicians had drawers full of connectors and software to diagnose each of the major automotive brands, as each one had its own protocols and interface. Starting with vehicles produced in 1996, On-Board Diagnostics Series II was the EPA-mandated system to help make vehicle emission control and diagnostics as standardized as possible. Every OBD-II-controlled car, including your 2002 Galant, used a trapezoid-shaped data link connector to gain access to the OBD-II system for monitoring and resetting the system.
Open the driver-side door and adjust the driver's seat as far back as it will go.
Position yourself so you have a clear view behind the dashboard and above the accelerator pedal.
Look just behind where the dashboard ends and above the accelerator pedal, find the trapezoid-shaped, black receptacle. This is the DLC on your 2002 Mitsubishi Galant.
