1994CamaroZ28

after headers everything was running perfect. then i installed my o2's hell broke loose basically, from a stop the ses light would come on etc so i took em out everything a bit better, Now when im at low rpm my car spits spudders backfires tries to die you name it

i was going down the road around 15 mph in a block span all it would do is idle drop to 500 no throttle etc. then would either die or idle back up and backfire.

the o2's are not plugged in runs fine for a while then will start doing whats stated above any and all help is really apriciated im just so tired of having car problems