When I start my car the idle is pretty high around 1600 rpm. After I start driving the car and get up to about 30 mph it hesitates or jerks a few times. Then the check engine light comes on and it stops jerking. After that the idle revs from about 750 to 1500 like a pulsing idle. And randomly it will idle normally. Check engine light stays on. What's causing this little bit of jerking and erratic idle?

 

Pull the code for the Check Engine Light!