[eesh]

pawn Код:

public IsATaxicar(carid)
{
    new model = GetVehicleModel(carid);
    if(model == 420 || model == 438)
    {
        return 1;
    }
    return 0;
}

There are 2 models of Taxis. You might be entering the other type.

Also check if the taxi job is 2. It could be some other ID?

pawn Код:

else if(newstate == PLAYER_STATE_DRIVER)
    {
       if ( IsATaxicar( GetPlayerVehicleID( playerid ) ) )
        {
            if( PlayerInfo[ playerid ][ pJob ] != 2 )
            {
                RemovePlayerFromVehicle(playerid);
                SendClientMessage(playerid, COLOR_GREY,"You don't have keys of this car.");
            }
        }
    }