I have a 2000 ford focus 62,000 miles. The past few weeks my car has developed a idle problem getting worse as time goes by. When I pull up to a stop after the car has warmed up or when its cold the car will not idle, now even stalls out and when I proceed it stumbles. It has got to the point I have to drive with one foot on the gas and one on the brake.
Does the check engine light come on during any of this or is it currently on? Has the vehicle been tuned up recently? If the check engine light comes on and you are able to scan the computer for fault codes, it will give you a clue as to what's happening. Let us know.