Ok I changed the spark plugs and cleaned the buterfly valve in the intake and then the car would not staying running. It was dropping down to about 500-600 rpm before it would stall out. I replaced the idle air control valve and now will staying running but stalls out every once and awhile. I still notice that the rpms fbounce back and forth from 600 to about 750 when at idle. Could this be an egr valve issue or something else?