My Saturn idles at 2400 RPM; I’ve replaced the Air Idle Control Value, the Throttle Position Sensor, all with no luck… Could you give me some advice on how to bring down the ide?
Yes, find the vacuum leak. Vacuum leaks can occur from vacuum hoses. Disconnect the vacuum hoses, including the one to the brake booster, one at a time, and tape over the holes on the intake manifold. Does the engine idle slower with a vacuum hose disconnected? Check the large plastic intake tube for cracks and fit. Check the intake manifold for cracks. I hesitate to advise you to use a vacuum test gauge on the intake manifold.