I've noticed my truck making this loud clattering noise. There is no check engine light until i pull the vaccum hose off and then it had a 1537 code. I believe this noise has to do with the imrc system. My question is which of the three parts do i need to replace?
http://www.youtube.com/watch?v=xnPHy...ature=youtu.be

If anyone else has a similar problem ive found out what it was. The bushings between the valve assembly and the intake where gone. This was allowing the valve assembly to vibrate againist the intake manifold. Intake replacement fixed it.