stalled twice on tick-over

[adam_socks]

right...this morning when i started the car the revs rose to just under 1000, then dropped like a stone and it stalled, so i re-started and it happend again. third time when the revs rose i gassd it a bit, then let off and the revs stayed at about 600, then all the way to work whenever i stopped at traffic lights the revs dropped to just below 500, surely this aint right.
Any ideas whats wrong?

 

[Richy59]

I dunno why its happening but this also used to happen to my old car whenever it was having a bad day. I thought it was just age but maybe not

 

[SC03OTT]

mine did this last week. turned out to be a faulty o2 sensor (i think thats what they told me). you got any dash lights on?