I let them have it for 4 days but the light wasn't on. They "didn't find the skipping." That was a week or so ago. Taking it back today.
Was the light on prior to taking it in, because the codes will be stored in history and be able to read regardless of whether the light is on or not at the time, unless someone has went in and physically cleared the codes from the computer's memory.
Bottom line, if they can't properly diagnose the situation, find another dealer. Don't buy their bull shite of "there is no code"