NHTSA Complaint #11552376 — 2012 KIA FORTE

So my check engine light kept coming on and my car has trouble starting. Light is now on all the time.The code says it's a intake manifold runner control. I called kia they said the part is obsolete because my car is 11 years old. It makes my engine knock and shake and kia here in parma has been no help. They originally said part was around $79 kia motors was able to find 1 but now dealer telling. Me it's $400 can't get check engine light off or my engine to stop shaking without the part but not when the price is tripled. It's been in kias shop for a recall and they didn't know what to do about the part or the knocking .