Well after countless hours of trying to figure out my missfire problem after the header install, it is finally over!!!!!!
I was able to get it on the scope today and the #5 cylinder was acting up. First off I changed the Plug wire but that didn't do anything. So I went and bought another plug and sure enough it's fixed. I'm so pissed that one of my new plugs was no good!!! It cost me so much time

I'm still experiencing a bit of missfire below 1500rpm when I give a lot of throttle, but above that everything feels good. Does anybody have an idea why the car is doing this??? Could it be knock????

 

I replaced my coil and my ~1500 rpm miss went away.

 

Congrats, I had the same issues after my SLP header install they are cursed........

I would guess EGR for your stumble, my problem ended up being a bad O2 although the car still doesn't feel 100% the dyno will tell for sure on the 25th

 

maybe its ur Opti?
didnt u recently havea problem w/ your water pump?

 

Well I spoke too soon. The car is acting up again.

It runs better, but it still missfires

 

Check:
EGR
Coil Wire
O2's
MAF
Wires
Plugs
Opti

Get someone to scan your car

 

coil is high rpm stumble, probably your egr.

 

dirty coil end is ussually a stumble, bad coil is ussually a dead coil.

 

I removed my egr

 

get that opti in there man, damb!