Backfire problem

I have no idea of what is going on with this car first thing is the car will backfire when i do high rpm shift then it will shut off or it will backfire shut off and then turn itself back on. Second if I am at a light or stop sign when i am in netrual it will be stuck at 2,000 to 2,500 rpms then die don't know what the problem but its is pissing me off.



98 eclipse gs

well i found the problem and it was the coolant sensor plug. but the check engine light is still on so i connected the computer up to it and it showed that there was another problem so does anybody know what this is Manfacurer control P1698