could be the cars computer going out,they are usually pretty cheap in the junkyards.i know a junkyard that sells all computers for 25.00 each and they are easy to replace.you just have to find out where it is located in your vehicle.usually the passenger side floor area beside the right leg,against the wall.the junkyard im talking about is on west 3rd street in dayton ohio it is called affordable auto parts.hope i helped