I did some quick research and found that since 2008, Kia had redesigned the intake hose and changed the size of the second resonator chamber, so my old resonator wouldn’t fit the current nozzle. D’oh! Very unhappily, I took the entire thing back apart and asked Carol to take it to the dealership to see if she could get a new resonator. I gave her the hose so she could make sure it fit before buying the new part. If they didn’t have it, I’d have to order it on eBay and wait more days for it to arrive.
Today Carol went to the dealership and they had the new part on hand for $25. Hooray! Now I have to reinstall the entire thing again tonight. But at least I know I can do it.