For some reason, my car dies and when I start it back up, it'll work fine until I stop and then it'll die again. My check engine light is on and Auto Zone told me my knock sensor needs to be replaced. The car runs good when I fill the tank but when it gets to about 3/4 of a tank, it starts to mess up. Is it because of my knock sensor or could it be trash in my tank. They diangnosed it and the knock sensor and the coolant sensor and some type of emissions sensor was bad. Please help, i'm still making payments on this car. I'm ready to give it back!!!