ok like a month ago my car started like lagging when i was driveing because two cylinders weren't fireing. cause i had a bad head gasket. so i fixed that and go tthe car back running. then when i got the car back i'm driveing it around the car wasn't driveing right. so i get to my house and i pull into the driveway and the car keeps reving it selt below 1 grand and the service engine light is flashing so i shut it off. i do have platuim spark plugs and i changed them. anyone got any ideas what could be the problem. thanks kris

 

Have you checked the codes?? What were they? Thats a great place to start.