I just got my alternator replace and when i was driving back I relized my idle was jumping. It felt like my cars wanted to die out it was reving from 900 back to 700 back to 800 etc. It even went up to 1100 rmp while idle so i brought it back and they check it but say they couldnt do ne thing. Can someone tell me whats wrong with it?. Dont make it too complicated, not too knowledgable with this stuff

 

is it just your idle thats rocky check your o2 sensorit its can be fixed with a little turn of a flat head screw driver and the left side of under your hood turn the thing a little bit you will know when to stop

 

i dont think the fact that you got your alternator replaced has anything to do with it.