what your describing sounds like the typical user idiot10 error, when you changed the injectors, there are little black filters in the end of each top of the injector,these tend to fall out in storage ie: your dressor drawer or tool box! what most people who arent paying attension do is let them fall out and when they put em in the car there missing 2 or 3 of the filters, so it runs like shit cause the filter also restricts the fuel flow, look at the top of each injector make sure you got a little black insert in each one. That should solve the prob if your missing em then pull some from other injectors laying around and make sure all four in your car have em!