Stao - sorry if you miss understood, I'm not saying it's turbo related. The boost is sitting very stable at 14/15psi constantly, the car just feels like it pulls then doesn't then pulls again. As if I'm opening and closing the throttle. It's a really strange feeling, but now that I think about it it's only been since I installed the front shaft, I will do the diagnostic to turn off the 4wd and see if it still does it, maybe there is just too much driveline for my tune to handle. It's very hard to diagnose a particular issue when you have 2 other problems at the same time.