I almost had the same problem. I stripped one of the bolts. I bought a new gasket and used some penetrating oil on the other bolt while re-installing the EGR. The new gasket is heat sensitive and will adhere to the UIM and EGR when heated. My problem was insufficient EGR flow, so I cleaned out the throttle body, but stripped the EGR bolts upon re-assembly. The one bolt is holding sufficiently after about 2 weeks.
