[rhandwor]

Try spraying carb cleaner around the edges of the intake and around the base of the throttle body and pcv hoses. If you find a vacuum leak it will smooth right out. Use a bolt and plug vacuum line to the vacuum booster if it stops replace. Try plugging the vacuum to the egr and see if this helps if it does check the solenoid. Sometimes the vacuum control solenoid goes bad. With your mileage the egr is probably leaking unless its been changed.