I also question the diagnosis. I don't see how the IMRC would cause that.
There is no need to remove the intake manifold to change the IMRC box. I found it necessary to remove the throttle body, but others have posted that they did not need to. They must have smaller hands then mine. Unbolting the box from the front valve cover is easy. Undoing the other end of the cable below the valve body is not so easy.
Anyone wanting $300.00 labor to do that job is either inexperienced or he is a thief. Either way I would not want him working on my car. Even taking the throttle body off it should not take over 1/2 hour.
