Some days ago, the cylinder head was serviced and the valves adjusted, because my car had an oil leakage that damaged the air sensor. At the same time, almost all the sensors were cleaned. However, it now happens that, when starting to drive, the vehicle suddenly stalls. The fuel pump has been checked and it seems to be alright. But the failure is still there and I do not know what else to check. Could you please give me your opinion?