Chrsity

I have an alto 2015 Indian model. Its check engine light is on. The problem I face is, after ignition is on, with much difficulty I have to accelerate. On the first gear very difficult to move. When I release the clutch the engine tries to shut down. With constant accelerations I am able to move the vehicle slowly. I took it to a mechanic he said it was with the oxygen sensor by scanning the vehicle. Further he said I have to change the clutchjplate , clutch bearing and pressure plate. I did change the pressure plate ,clutch plate and bearing with the new one and the oxygen sensor with a recondition one. But the problem still exists. Please advice me to resolve the problem thanks and regards Christy