I've experienced pixelation on just a few channels. It was caused by a signal issue that was fixed when Cox line techs made repairs. Unfortunately, getting Cox to do that isn't always easy. You can start with scheduling a tech with a long ladder (if your drop line comes in from a pole). Have your signal checked at the tap. If the tech finds an issue with the main line, he should escalate it to a line tech. If there is a main line issue, your neighbor(s) sharing the tap should be experiencing a similar issue. If you know them, ask if they're having an issue with the same channels. If yes, ask them to report it to Cox. Multiple reports can sometimes escalate an issue.