LS2 CTS-V TPS fluctuates

[MichaelSuch]

Hey everyone, this problem just started 2 days ago. While holding the pedal at a constant angle, usually around 25% in 6th and cruising it felt like I kept tapping the brakes. I ran a log and the TPS while bounce from ~20-28% for a few seconds then go back to 25%, then a start bouncing around and go back to 25% again. At idle the issue doesn't happen, it's always at 18% and idles at 850. It doesn't seem to happen at WOT either, it's always at a constant 99%. I don't think the issue is in the tune. But rather with the throttle body. I'm not familiar with LS engines at all really. Does the ETC motor need cleaned? Or maybe just the throttle body? Or does it need re-learned? The car is a 2006 CTS-V with Pacesetter LTs, Magnaflow Catback. IAT relocate, ATI 10% UD pulley. Everything else is stock. Any help would be greatly appreciated.

[MStefak]

Have to touched the electronic throttle tables ?

[LSxpwrdZ]

Put some fresh grounds from the battery to the chassis and chassis to engine. Had a 05 LS6 car come in doing the same thing and grounds fixed his. I'm guessing the factory grounds were corroded so we cleaned them and added 4 gauge wire for a couple of new grounds and all is good now.