The clue that draws attention to the (CKP) Sensor has to do with the "Bumpy, Rough Road" phenomena occurring close aboard to these power diminishing events. That strikes me as possibly relating to the Reluctor Wheel that has 60 discreet "Notches"...Minus 2 of them ...cut into its outer orbit to demarcate the position of the #1 Cylinder as it approaches Top Dead Center. This means that each "Point" on the OD of the Reluctor Wheel represents 6 Degrees out of a 360 Degree Circle.
That Reluctor Wheel is made of Mild Steel and in some other engine Platforms has been known to Break Loose and Spin Free of its Weld On Points at the front of the Crankshaft. Since "Timing is EVERYTHING" as we all realize for efficient combustion in each cylinder and the expected power it should produce, anything that might alter either the (CKP) Sensor itself in the Lower Engine Block or even the Reluctor Wheel itself rolling around directly underneath it can affect Engine Power if they become changed in any way.
There have even been some instances where the Reluctor Wheel was simply CRACKED all the way through from its center around the Crankshaft to its Outer Edge. And so the Engine only manifested these Power Loss and Stammering Events with Timing Problems at a High Enough RPM Level to allow the Reluctor Ring to EXPAND away due to the Centrifugal Force acting well enough to change its Outer Dimensional Shape and likewise... its Relationships with the (CKP), an obviously Subtle and Very Frustrating Problem to have to Diagnose.
The PCM relies upon the MAF, the IAT, the MAP, the CPS, the CPAS, the ACC Pedal, the Throttle Plate Position, the Upstream O2 Sensor ...and the (CKP) Sensor ... to allow the PCM to decide on when to Fire the 'Coil Over Plug' Ignition System once inside each Cylinder per each 4 Stroke Event BTDC and provide the Spark Plugs with the necessary Secondary Voltage while coordinating How Much Fuel to Deliver and When it gets SPRAYED by the EFIs ... ALL based upon All of these relationships All behaving as they should every 720 Degrees of Rotation on every single Four Stroke Engine Cycle.
So running over a "Bumpy Road" just might allow a Loose Reluctor Wheel to "Chatter" in position where it rides around on the Crankshaft Base Circle just enough to skew the Reluctor Induced A/C Voltage developing inside of a normally operating (CKP) Sensor while it inductively tries to create 60 Alternating Current Events (minus two) using a Permanent Magnet and a Fine Coil of Wire for signalling the PCM to "TIME" these events in succession... by creating an A/C Sine Wave and alerting the PCM with Variations in Signal Frequency and Amplitude.
One Last Thing...that really is The First Thing the AIR entering the Engine encounters... Replacing a Dirty Air Filter as a possible obstruction during demands for Engine Power and Torque would not hurt...either. (Sez... The Oldest Coot of them ALL...)