First and foremost; posts that are posted in the cheat codes/gameshark etc sections are moderated. These sections are strictly for posting cheats/guides only. These sections are moderated to keep out comments such as "thanks" "it works!" and so forth as these types of replies aren't cheats, please use the thumbs up/down feature for this. That being said, adding your own cheats, custom gamegenie/gameshark etc codes are allowed, they will fall into the moderation queue as mentioned to keep out irrelevant content though but yes, you are welcome to add your own codes to a existing thread. If you would like to give feedback on something, then please use the consoles chat forum for that and other discussions related to that console.
As a reminder to some users here, I'm going to give a refresher/update on some rules concerning gamehacking codes and cheat codes. If you see a thread or a post where the author wasn't attributed properly (and you are the originator of said code; do not report it if you are not the originator of the code or your account will have appropriate actions taken against it!), then click the report button and provide relevant information on who should be credited and provide an original source from a CMS, (website, blog, forum, etc) that has a proper timestamp. Point out which codes need attribution and to what username should be credited, your report will be examined and changes will be made where applicable.
For more information, refer to this thread