After coming to stop, i press on the gas, and the engine revved like it was on neutral while it was still on drive. It kept on doing this afterwards, and we realized it needed transmission fluid change. We completely drained the transmission fluid, added new fluid along with a new filter. There was not much change with the problem, later i realize the car will drive on 2nd gear, and when i switch to drive, it will shift to 3rd, 4th ,and so on. Will there be a problem with switching from 2nd to Drive constantly? If so, how can this problem be fixed?