Set this code: P0221
 

This code pops up after a setdy speed drive. When it does come on I get a "entering low power mood" also about ½ of the time a check engine light comes on. The Traction Control light also comes on. If I turn the engine off and then restart the "entering low power mood" and The Traction Control light go out and engine runs well. The check light will remain on until cleared or required number of restarts have passed. This is a random item although becoming more often. The first time it happened was after about a 120 mile drive cruse set drive at 75 MPH. The car has 135,000 miles with no prior running issue, so very happy with car. The test steps are do able but looking for some history of similar issue.
No other codes have been set. Have never ser any code in past. Thank You.

Have a read about the code and tests to confirm the problem

P0221 Throttle/Petal Position Sensor/Switch 'B' Circuit Range/Performance Problem OBDII Engine Light Trouble Code | AutoCodes.com

Check the wiring at the throttle body harness for loose or damaged wires/ connections.
Also at the foot throttle pedal wire harness.

X2. In most cases it is caused by loose or broken connections.