I replaced the crankshaft position sensor on my 2013 Koup SX 2.4L with a new, OEM, Kia sensor purchased from Amazon for $44.If you're buying sensors at autozone, advance or o'reilly/carquest, that COULD be the problem. Aftermarket sensors suck. It's best to buy a genuine sensor from your local KIA dealer. I worked at 2 of the 3 parts stores mentioned and that's why I WON'T purchase sensors or electrical parts at a chain store. Cheap crap that is often defective out of the box. Do yourself a favor and get your sensors from a KIA dealership or buy them online from a KIA supplier.