Stuttering and lunging

so for the past year and a half my formula has been stuttering at idol occassionally amd i have to yam into it and it corrects itself. originally it did it and i replaced the wires and it stopped, again then i changed the plugs, now i've taken it to a dealer and they said it was the o2 sensors so i changed them. for a week it didn't do it but yesterday in the rain it did it. it only does it after i've driven it and it has warmed up then i shut it off for a few minutes and getr back in it. at a light it will idol rough and then suddenly want to jump forward. the mods i've done include EGR and AIR remoaval, SLP longtubes, MAF, intake and lid, and it's back on the stock tune for now. I am redoing the engine next month withg stage 2 heads and a cam with a total rebuild. any ideas as to what the hell is doing this?