Mine ended out being the fuel pumps with the erratic behavior. I have to take it in three times over the course of 4 months as it would never reproduce the issue while at the shop. I finally left my car at the shop for a week and a half until the mechanic could reproduce the issue on the spot and look for the trouble code. The wiring in the fuel pump only made it work off and on. And over the 4 months it got worse and worse.