Replaced O2 sensor, reset PCM, mpg's plummet

[Mr. Pig]

So this past weekend I put a new Bosch front O2 sensor in, and then unhooked the battery for a while to reset the computer. This morning when I go to leave for work, the car starts hard and idles rough, I expected that much, and the mpg's were really bad. What I am wondering is, how long can I expect to wait before the fuel trim tables are reconfigured? I've heard of some not liking the bosch sensors for one reason or another, should I have just went for a better quality sensor? Bosch was all that was offered at autozone. Thanks for any advice.