My girl has a 2007 suzuki xl7 and when i was driving it, it started making a******** feeling and someone told us it was the coil pack for number 4. We changed the coil pack and it still does the same thing, so we changed the coil pack on number 6 and it still does the same thing, the service engine light came back on. It is not the transmission. What could it be? Need some help and feedback please anyone.