just finished installing my headers today and the car stumbles and bucks at low rpm, i am running an open y-pipe right now and the o2 sensors are installed, i left stock wires and plugs in since my car only has 33k miles and im planning on changing them a little later on, did anyone have a similar experience or know whats wrong? thanks i need some help

* i have also took out the air pump and blocked off the egr

 

In many cases when something like that happens after a header install, its a plug wire thats been burnt from laying on the headers. See if one isnt touching a primary enough to get burnt.