Fixed - it was just as I suspected too.
Thou shalt make simple ground loops
It wasn't resetting, the indicator LED on the arduino blinks when it tries to init and when it fails.
Todo
*find a pnp transistor
*move the stickduino power "jumper" Or, make a power USB cable
* wire up the 33290 chip
* wire up an RJ45 socket
* button time
Does anyone know if the 33920 chip absolutely needs the ECU voltage on pin 1? Or if something around 12V will be fine? I can't seem to figure it out from the spec sheet...