alright when i rev the motor at idle just a quick tap theres a hiss like an open intake makes a sucking hiss noise, then the motor roars a milisecond later. i always thought it was from my air filter box sucking in air, but i realized its coming from under the intake plenum around the fpr and egr. is this noticable hiss supposed to happen or what??

 

Possible bad gasket under the EGR valve sucking air. Just a thought!!!!!

The Trickster!!!!!!!!!!!1