spark plug replacement

mrb friends yesterday I changed the spark plug of my car but the place I changed did not test the heat, but I bought this spark plug from the bosch outside, but it was a bit of a problem. If there is a situation, what will be the symptoms and what kind of a malfunctioning vehicle 307 2004 model 1.6 16v

When he said he did not give up, my friend was not bored or could not make the connections completely or I was like a novice.

there are points to be considered in spark plug replacement
For example, the nail of the installed spark plug should not touch any place during the installation
In addition, the spark plug should not be too tight or loose between the two, of course, the masters make the adjustment according to their experience.

Actually, it is not a very difficult process to replace the spark plug. I changed it once in a while now I always do it myself. In this way, I do not face such situations.