GTkllr

So I started having his problem lately now that it's gotten colder. It'll only do this occasionally, I'll start it up and let it warm up for about 3-5 minutes, and take off. As soon as I do it starts to misfire and hesitate quite a bit unless I give it quite a bit of gas and it'll still pop and misfire a little bit. It will throw p0300 and p0131. It'll do this until I drive it around for another 20 minutes sometimes less, but after I do, it'll run like normal. Looking at the 02s on the scanner they seem to stay sometimes at a certain voltage sometimes and change slow, which i know they shouldn't be. LTFT sit at around -9 for both banks. Could this be the problem? I do have longtubes btw.