engine idles way too fast now

1998 Saturn SL2 Auto transmission. Suddenly idles too fast right after I changed the battery. Is there a connector I might have knocked loose? In drive, the idle causes the car to go 20-21 mph and idle rpm is about 1900. In gear stopped, the idle initially is high but drops to 900-950 rpm. No check engine light. My wife normally drives the car. She reports she is now afraid she will wear out the brakes. I just drove it to confirm the above numbers.

I don't have a code reader. I can take it to a good shop tomorrow but they are closed today for the holiday.