I have a 2001 Focus SE 2.0L SPI. A few months ago I had my fuel pump replaced under ford recall 03n01, and then just a few weeks ago I started having idle problems. First it was just at start up and seldom at stops. Now it is at start up, worse at stops when it is in gear, a bit better in neutral, and has even stalled twice while in park this morning. I have been searching the internet and comparing what I know about these darn focus's. I truly suspected a vacuum hose leak, but thought maybe the Mass Air Flow Sensor, Oxygen Sensor, Idle Air Control Valve, or even the spark plugs. So I went first with the easiest and cheapest first. When I started the car I could hear a slight hissing noise coming from the backside of the engine near the throttle body. Good sign. Ends up the vacuum hose that runs from the valve cover (the cover that has the oil cap on it) to back behind the engine and under the throttle body, into the manifold, had a worn and ruptured rubber "elbow" where it connects to the manifold. I am going to replace it in about an hour. I'll let you know how it goes. 99% sure it is the problem.
Wednesday, February 13th, 2008 AT 2:07 PM