Tells you that the old sensor was bad, and making it run hella rich, since it thought it was lean all the time... Maybe disconnect the battery for a bit to clear any stored memory of the lean conditions, and then try again in an hour or so. Touch the cables together before hooking back up to neutralize any residual voltage.
It might just be that it doesn't quite know what to do with the new input of balls out rich, and need to forget it was reading lean and trying to dump fuel for so long...
Rob L.