I posted about this a while ago. After it has warmed up the car will not sit at idle. The revs cycle between about 1200 and 2000 every second approx. Following suggestions here I drained the radiator and refilled it with 50/50 coolant/water, and I inspected all the hoses/lines looking for leaks. Everything looks fine. I also blasted carb cleaner into the manifold. I have seen suggestions that I need to inspect the O2 sensor and an idle control valve, but I don't know how to locate these. The engine layout pictures I've located are from the US, while this car was sold in Japan, 1.6L engine.