Probably Not. The cracking and popping sounds are the same, but the location the sound came from is most likely different. When people “self-adjust” the most probable result is that the joints above or below the problem joint are cavitating (the term used for that popping sound). This produces a sound similar to the one heard when a chiropractor adjusts a joint but the actual joint that is restricted or otherwise not functioning properly is left unchanged.
As you can see, the image on the left depicts that there is in fact a subluxation present. The middle picture is what most likely happens when a person self-adjusts a problem area. The joints above and below the problem joint cavitated but the problem joint remained the same. On the right, the problem joint was addressed properly and the rest of the spine is now in proper alignment while leaning to the right.
IT IS NEVER RECOMMENDED TO ADJUST YOUR OWN NECK. IT COULD CAUSE SEVERE UNWANTED OUTCOMES LIKE A STROKE OR DEATH IF PERFORMED BY UNTRAINED INDIVIDUALS.