Ok before everyone says use a search i did and can not get one single answer. And everything they are suggesting I have done. My car is a 95 lt1 and it seems to die out around 4000 and higher. Also in the lower rpms if I give it alot of gas it has some hesitation to it. I have replaced the coil the wires and plugs. Also I have did all the egr stuff with all new parts and lines. The only thing I havent replaced is the opti. My car has 86000 miles and Iam worried that it might be starting to go. I have another but dont want to put it on if the problem is something else and easier. lol. Any suggestion would be great.
-Thanks Brandon

 

Check the Opti harness yet?

 

might be a fuel problem, if not maybe some screws cam loose with the opti