My check engine light came on. I went within a few hours of my light coming on to get it checked. The code came up and they told me it was a "mass air flow sensor". I got it replaced within a few days. Not even a week later, my check engine light came back on. I took it back, the same code came up. I'm not sure, what i should do. When i start my car and when i'm using my break, my car vibrates, and almost like bounces, so much that my steering wheel bounces.