2003 focus, 90,000 miles 2.3 engine. Rough idle sometimes stalls. I removed the air intake tube at the throttle body and the engine idles so i assumed the the air filter was bad but after taking all the air tubes, hoses, boxes i can find an air filter. (this is a 2.3 ztec engine with the intake manifold on the radiator side) The Haynes repair book has no photos and little information on the 2.3. My other thought was to remove and clean??? the idle control valve which i think is a cylinder shape about 4" long, mounted verticlly, on the radiator side of the throttle body. Anybody have this problem or ideas .. . . thanks Don