Sub Giving Feedback, Not sure what to check next. . . Options

[My94RedCelica]

Quick question for you all. I tried a search but didn't find what I need. I have a Kenwood in dash DVD player connected to a Kicker CVR 12" The set up and wiring was working completely fine, but after a week I started getting horrible feedback from the sub. My friend had installed the headunit, so I went back and traced the wires. He had the RCA, remote, and power wires running together. So I seaperated the RCA's from the remote wire and I still have feedback. I checked the amp ground. moved it around a little. Now I have a humming feedback, and it gets higer pitched when I hit the gas. i'm not quite sure what to check from here, so any advice would be appreciated!