Battery voltage is 14.2. Weird. Wonder why the ECU sees so much less?
Also, I wonder if this is a hardware. Come to think of it, I've just re-done the inlet and the MAF is now welded on a bend with no flow straightener. I bet that it's my own fault that it's like this...
I had a battery once that showed good voltage but would fail a load test. What is battery voltage with the engine off? Same thing with an alternator. In the case of the alternator, the brushes had worn almost completly away. Not saying its your issue but it sucks when the simplest things make things seem way more problematic than they really are. both tests can be performed in like 5 minutes at your local auto parts store usually while still in the car.
Assuming you checked grounds and voltage at the alternator and voltage at the battery while both are under heavy electrical load. Maybe it's time to check the resistance between the power lead ot top of the battery juction/fuse box and the pin for it in the connector for the ECU. it shouldnt have a high resistance.