[sunman]

Intermittent electrical problems are often caused by bad connections.
P068A = Engine control module power relay problem.
P0507 = High idle.
P0681b = MAF connector problem or throttle position sensor prob.
Tap on these parts with screwdriver handle when problem is occurring.
If there is no change when tapping part I would use cold spray for thermal failure.
The scanner will indicate what part is bad or losing connection for you to check/replace.