My ESP light came on and now my car stalls and will not go over 60 MPH. We took it to a shop to have it diagnosed. They said it was the MAPP Sensor. We replaced it and the car is still doing the same thing. Also, my check engine light came on. I had that diagnosed as well. They said it was my gas cap. I changed it, but recently found out that I was sold the wrong cap. Can some please help?