Help with 2000 neon issue

drive the above and recently have rough idle, fussy acceleration and a P1684 code when I do the key dance thing, any suggestions?

P1684 “The battery has been disconnected within the last 50 starts”! That’s really serious stuff, Man!
Do you have a problem with the car? Ok, there might be some kind of problem. Have you disconnected the battery, recently?

battery has not been dis-connected, thats what I scooped on the net however the check engine light has come on and wanted a “feel” for this before I went a spending!

If you didn’t disconnect the battery, something did…something like a poor connection. Start with the battery cables. Disconnect the battery cables and file, sand, or use a round wire brush to remove the corrosion from the inside of the cable loops (or, wire brush side mount battery terminals). Smear with petroleum jelly and reconnect the cables. Check the other ends of the cables at the starter, engine block, fender, and attachment to alternator for corrosion and good, clean, snug connections.