I've never known a vacuum leak that could cause a low idle.
Ahigh idle, sure, most of the time, but a big leak, that usually induces a stall.
I've never known a big leak to create a low idle, that feels like a stretch to me.
There is only one thing I have ever found to be at fault with a low idle and that is a cylinder running below its potential.
Under load and at speed it can ride open the coat tails of the others but at idle, that weak player will show his cards.
Fire it up, set the idle speed to spec in park/neutral (850?) then start pulling wires, one at a time and see if they all produce the same amount of work.
My money is that one of the cylinders is not pulling as hard as the rest.
Could be as simple as an oil leak into a spark plug well shorting out the plug or something as sinister as a burnt valve, but diagnosing the actual cause before pulling the trigger on the parts canon, is a much more satisfying method of reserve depletion.
All TV's are a negative influence on cash reserves, 4WD just cuts the commuting time in half!