IMRC's are simply ports that open much like a 4-barrel carburetor. At low Rpm's they stay closed and are opened by vacuum pressure as load increases. Here is a picture from a V-6. You can see the valves in an open stage.
IMRC Ford V-6
Unless you drive like an old man in Florida, you probably DO have a slight vacuum problem. I have seen this code many times in the past and vacuum lines going to the IMRC control or where they meet at the vacuum distribution usually causes it. You can't actually see the valves unless you tear it down. Go through your lines with a fine toothed comb and if you still don’t find a problem, try running a Sea Foam treatment through the booster line and in the tank to clean the shafts. If that fails, have your control tested.