I recently changed my gear shift box on my 1996 lexus ls400, after changing it i’ve had a few issues. first my speakers all went out except for the back right side door. secondly the car starts great and acts normal, but after a few minutes shuts off completely. driving feels normal then the car just shuts off, the lights stay on but the engine shuts if completely. sometimes before turning off the check engine light flashes on and off, as well as the “trac off” light. additionally while in park the speedometer starts moving up and down before the engine cuts off. i have no idea would it could be, if anyone has any ideas it would be much appreciated!