I should think that if you can start up the car, then it should be okay. The only difference between the peak and hold and saturated injector varieties is the voltage required to fire them. They each have a different impedence, the difference being about 10 ohms. The 4th gen peak and hold injectors are 340cc, while the 5th gen are 290cc. The only difference would be the flow, but I'm pretty sure you'd be noticing if you were running too rich by now.