@Gaz - I think P0350 is a "catch all" code thrown when the
ECU detects missfiring/rough running but doesn't know why. Your
MAF readings look about right for a v8 (assuming engine at idle) and the O2s are switching ok (maybe a bit slowly but they are ignored on cold start anyway). What do the long term fuel trims look like? Should be within +/- 10%.
Have heard of a few AU V8s with cold start missfires. If it's not ignition related (assuming you've tried new plugs, leads, coils) then it's probably insufficient enrichment in open-loop warmup mode. A few things I can think of - make sure coolant temp sensor and intake air temp sensor read roughly ambient temp after sitting overnight. Check the
MAF readings on cold start - maybe it's reading low until it warms up a bit.
I've also received a OBDII Bluetooth adapter (v-gate scan brand - $20) and got it working the the Torque Pro Android app ($5). The standard OBDII gauges etc don't work but custom PIDs can be entered. Here's how to set it up:
Plug the BT dongle into the car and turn ignition on. Go to the phone's settings menu and pair the bluetooth device.
Install Torque Pro and go to the settings menu - OBD2 Adapter Settings. Tick the Faster Communication option and tick the Don't Calculate MPG/Fuel option (it won't work cause it tries to use standard mode 01 PIDs which the AU doesn't support). Under bluetooth settings select the device you just paired.
Create a new vehicle profile. Most of the settings in here don't really matter but the important ones are near the bottom. Set the OBD2 protocol to SAE J1850-PWM. Under the "very advanced" setting at the bottom enter the configuration string as follows:
ATSHE410F1
Click save. Then you need to enter the custom PIDs. Go settings/manage extra PIDs then add custom PID. Enter the mode and PID as described a few posts above. E.g. for MAP: under the Mode and PID setting enter 221440
set min/max to 0 and 102, and set equation to (A*256+B)/4 , and OBD Header to Auto.
Then go to Realtime Information (from the start screen) and delete all the default gauges. Add a new gauge and set it to use the PID you just entered, and it should work.