1684 The battery has been disconnected within the last 50 starts
In the 1998 Intrepid ES, 1684 indicates a problem with the catalytic converter. It probably is the same for the 2000.
Probably means battery disconnected or discharged within the last 50 starts.
P 1684 is "Battery disconnected within last 50 starts"
Trouble code P1684 means:The battery has been disconnected within the last 50 starts
P 1684 code refers to your battery being disconnected (it should go away on its own after about 25 physical restarts as long as you keep the battery connected). The P 1299 is a manifold pressure error. Listen for leaks (hissing sound under hood) and look to see if any hoses are loose or disconnected.
Trouble code P0755 means:Shift solenoid B malfunction
Trouble code P0500 means:Vehicle speed sensor malfunction
Trouble code P0742 means: Torque Converter Clutch Solenoid Circuit Stuck On
Code P0455 means "Evaporative Emission System Leak Detected (gross leak/no flow)"
Trouble code P1470 means: Leak Detect Pump Pressure Switch Low
Trouble code P0605 means:Internal control module read only memory (ROM) error
It is done flashing codes. If that is the only message you got, there are no codes present.