Code P1684 is what

P1684 is an informational code that means you have disconnected the battery recently. This code doesn't hurt anything, and won't turn the engine light on. If your engine light is on you have some more codes stored. If you don't have a code reader: Cycle the key from off to on three times ending with it on and watch the digital odometer display. The codes will pop up here.

I have a 2001 se neon I have the code p1684 and oil light is on when idling do you now why