my problem is when im driving at around 60 my car start to jerk and shake i change my spark plugs but its still doing it any one would know what it is

 

go get your tires balanced

 

haha..its not that i just got new tires and got it balance a couple weeks ago my car was running great until yesterday i cleaned the iac to see if that was it and it still does it the problem seems to happen after i get outta boost then it starts to drive like ****