It is considered generic because it applies to all makes and models of vehicles, although specific repair steps may be different depending on your car model.
Possible Causes :
Pack the connector cavity with dielectric silicone compound (same stuff they use for light bulb sockets and spark plug wires) and reassemble. Look for missing ground strap or a rusty ground where the fuel tank is grounded to the frame. Check for damage to the wiring harness connector.
Diagnostic trouble code U0257 is not difficult to diagnose and repair. Thus, it always pays to have a qualified technician to look after your vehicle should this error code arise.
Diagnosing this code requires the engine to be in good running shape, without unmetered air entering the engine. If other codes that relates to misfiring condition, lean running or air entering the engine is present, then you must first fix those error codes before U0257.
Fortunately, U0257 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.