My turbo works great until the EGT's hit 600, at which point it gets difficultto get back into boost if I have coasted (say after a steep hillclimb,) and I have to feather the throttle to creep up on 10PSI at which point it screams right up to 30PSI if I really wood it. As soon as the temps decline back to 550 or lower, it works perfectly again. Ford dealer claims to have cleaned the EGR, but I suspect that's it....any ideas?

Thanks,

JM

LA, CA

Just added Banks Big Hoss Bundle which reduces temps but when I finally get there, same thing happens, though it does cool much more quickly.