New to 8s frustrating problem

I'm having a problem with my newly acquired 05 Rx-8 where the car wont rev past 2k rpm. started with the radio display freaking out so i disconnected the battery to try and clear and reset the problem. when i reconnected the problem really started. since then i have checked and replaced coils, wires, plugs, fuses. my #2 coil was dead so i replaced it and the car ran fantastic until i turned the key off, then back to nothing over 2k rpm. ill post a video if that helps at all. any suggestions?:sweatdrop

New to 8s frustrating problem