Ford Contour 4 cyl running rough

1999 Ford Contour 130000 miles had a check engine light, which was tested at Autozone. Test said there was a massive air leak and a problem with the oxygen sensor. Replaced oxygen sensor, repaired two vacuum leaks. Was running rough at idle before repairs, isn't now. Now the idle is fine, but the engine runs rough in gear and while driving surges and stalls when you come to a stop. Replace fuel filter, PVC Valves, and air filter, didn't do anything. Hesitates badly when taking off, surges while driving. Check engine light is now off, and no faults are appearing during tests. Any help provided would be very appreciated. -Rick