So let me get this straight, the air regulator is the piece on the bottom of the manifold? It has I believe two large hoses on it and sensor that is connected by a plug that looks like a fuel injector plug? Impossible to get to without removing the tire and going in through the fender well? So if pinch either the line on the throttle body, or the large line on the common plenum (with a warm engine) the idle should not change?? It might be important to note, that my high idle at cold has not worked for at least 100k miles, this is controlled by this valve, yes? I will also check the thermal valve on the thermostat housing. The coolant is up, but I have recently developed a leak, might have something to do with a radiator with 309K miles on it. Thanks for the help.