4l60e overdrive issue

[Myself]

My buddy's nephew is buying an '02 K1500 4x4. It has the 4.8l. Trans seems fine everywhere except part throttle cruise around 45-50mph. It wants to jump back and forth between drive and overdrive. Leave it in drive and no issues, speed up to 60mph no issues. Stock gearing and tire size 160,000 miles. Only codes being thrown are knock sensor and fuel level cause the sender is bad. Would the knock sensor cause this problem or maybe a TPS out of adjustment? I really don't feel like it's a solenoid issue. Thoughts?

[homemade87]

A miss fire on the engine will also do this . May be knock related.

Also I have a friend that the lock up on the trans was hunting back and forth at light throttle . Checked everything , could not find the problem . Turns out the trans valve body has a type of check ball that wears and uneven hole . He pulled it apart and installed a shift kit to firm up the shifts and problem gone . We found out later this is a known problem for the 4l60e.