My wife went to start her 2005 corolla S this morning to be greeted with a completely flat battery out of nowhere, it was fine last night and it's a daily driver with almost 100k miles. I came home from work to see what the problem was, and after a jump start, the alternator was charging just fine so the battery was the problem. I replaced the battery and now the car idles verry low, like around 350 - 400 rpm. I noticed everything on these things these days is computer controlled. There was no check engine light either. Always properly maintained. The low idle lasted 30 mins while driving over town and then now idles fine, but under hard acceleration it feels like it's not fueling properly, spluttering like it was a rich mixture or something? Anyone have corolla troubleshooting experience seen this before or have any ideas what it could be???