I have a 2003 Mazda 6 with the 2.3L 4cyl. Motor. I am currently trying to pass emissions with a P2004 code holding me up. The shop I took my car to for diagnosis says I may have to replace the entire intake manifold for this issue? The intake manifold runner control is stuck open. My question is does anyone have experience with this issue? Any advice? They said they searched everywhere and found no vacuums leaks. Any help would be greatly appreciated!