ok, mid/high rpm really pissing me off
 

i have a REALLY bad stumble on the top end. I used to have a similar one when i first got the car (about 2 years ago) that made it pop and back fire at about 5800rpm. well, now its doing it at about 4500 :( its soooo annoying i can't get on it at all. I've changed the coil/wire, plus, wires, and fuel filter, and put in a new battery. I can't figure out wtf is going on!! is there a chance this is injectors? i'm down to it being a fuel related problem or the opti