I am not sure what it is but it is running wierd. It backfires alot, i changed out the drivers side plugs so far. can't really get to the passenger side until i can get it on the lift tuesday. I found out the old owner had japaneese plugs in it, i put autolite platnums in. on friday im gonna change the wires, what would you recommend for a budget, im thinkin of getting duralast for 26.99. i just put pacesetter headers in, there not long tubes, there mids. Could it be the o2 sensors? But there is also a knock comin from the engine. Please Help!!

 

I'd be willing to bet it's a torched plug wire. I really recommend going with an OTVC wire set-up.

 

I also just installed headers with trouble. It was running really bad. I found 1 cracked plug 1 burnt wire. It smoothed out alot. Then I changed the o2 sensors. Now it runs alot better, almost as good as before, except at wot. Still working on it, someone said to install lt4 knock modual, Im not sure what this will do. good luck my thread is probally 4 pages back.