My 03 MVP just started idling rough and lunging forward and back at stop lights. When the engine is at a higher rmp it's fine. The check engine light is not on. My mechanic cannot find anything wrong with the vaccum lines but suspects that is the problem. He says cannot find the problem without the ck engine light on. Has anyone else experienced this.

 

You need to do a tune up. You need to check if your check engine light bulb is blown. Go to autozone and ask
them to check your car with a obd2 computer. Use only ngk or denso spark plugs. Also change your coil pack. Do the OBD2 check first at autozone before you do anything else.