this could be a number of things from a simple tune up to some sort of fuel problem you will get a bunch of suggestions on here but to be safe let a shop find out what is. somethings are just hard to figure out with out diagnosing it on hand.
My check engine light came on and i took it to autozone so they could tell me what was making the light come on and they said it was the EGR. then i took it to a shop they also said it was the egr they replaced it but the same day the light came back on. the next day they replaced the egr...