Yeah those cam issues are a real bummer.
looks like you have already replaced ECU so that pretty well rules that out
unfortunately that leaves
Oil control valves
CAM sensors or cam sensor clearance
Sprokets/actuators
Have you seen this TSB re checking clearance on CAM sensors.
Be worth doing/checking as its fairly simple and low cost
http://www.ft86club.com/forums/attac...1&d=1375302652
Then the other TSB for cam sprocket/actuator,oil control valves
Bummer its doing it on both banks else you could probably swap ocv from bank 1 to 2.
and as your motec the DTC wont be much help.
http://www.ft86club.com/forums/attac...1&d=1375302652
Obly other thing I could suggest would be check your earth connections to chassis and motor since you have had motor out. Bad earths can cause weird stuff.
Maybe check batt/alternator volts to see its regulating correctly alternator is controlled via ecu, fluctuating batt volts could cause weird issues, should be pretty stably around 14 during normal operation.