My rover recently started running rough at idle and feels like it has a miss when under load check engine light is flashing when this happens. Once in a while it evens out and the light stops flashing. I replaced the plugs (gapped them properly), wires, and coil packs. Still doing the same thing, seems to be getting worse. Any ideas what else could be the cause? I recently put sone sea foam in the tank to see if it might clean up the fuel system.