I know this reply is a bit late but just to point out you can’t program another 168/328 via the Arduino Mega - you can only do this with an Arduino or clone that has a removable DIP package 168/328 chip - which has to be removed so that it doesn’t interfere with the target board/chip. Otherwise the TX line will be driven by two chips at once leading to garbled responses.
See the diagram at the bottom of arduino.cc/en/Guide/ArduinoMini - the host Arduino board has an empty 28 pin IC socket.