Rep Power: 0

While driving down the highway yesterday, all the panel controls died (display showed 0 rpms, 0 mph, etc.) the radio stopped, the headlights went down to parking lights, the ventilation stopped, the driver's side power window stopped functioning also but the passenger side continued working. The car is manual transmission & when I geared to neutral, all the items mentioned above began functioning again. But on changing gears it all stopped. Then the maintenance required light began flashing & the car began to decelerate. On the side roads at lower speeds, the car doesn't have these problems. The car starts up intermittently. The battery check showed it at 90% & connectors are good. Diagnostic checks showed bad knock sensor. Has anyone else had this problem or know what causes this problem?