Loping Idle/CEL Mystery

I just replaced the original battery in my 98' GL, and now the idle is loping, almost stalling at times. Also, the CEL, which has been on for close to a year with a 1580 idle air control code, turned off two days after the battery was changed. What on earth would a new battery have to do with the idle or CEL? ECM reset?? Any ideas on what to look at for the idle, it had been running fine.

lol, yea i know your problem. everytime you change batterys on these cars, you have to go to the dealership to reset the car to its basic factory settings. should run you around 50 bucks, or free. you don't have to worry about the car turning off or anything, at the very least the idle will fall to about 300. alternatively, you can drive the car for 1500 or so miles and that will relearn the ecm also.