On the Altima I had and probably on your truck as well, the egr valve is dependent on a back pressure transducer that prevented the egr from opening unless there was enough vacuum in the manifold. That is, it can't open the valve at idle. With the turbo, the valve would probably still open as long as the boost was relatively low. If not, this part might need to be replaced with one from a turbocharged car. Will the egr affect the performance? Of course- it exists to lower combustion temperature and power output! But can the turbo improve performance with an egr still operating? Certainly. Turbo VW's, Volvos, Fords, even Nissans have egr systems and are still very fun to drive.