Don't let it beat you!
I'm no mechanic. When my IRD went I cursed and spat fire for about a month deliberating how much money to pile into the car and how to fix the f***g thing. But I persevered, got some bits shipped over and lost a lot of skin off my knuckles - but I got it back on the road. I didn't even like the car too much before that - but I love it now. That was 2 years ago and its been Toyotaesque in its reliability sinceIts repayed me heaps for the effort I put into it.
For a fuse to blow there's got to be power going through it. You've swapped the fuse box itself - so its unlikely both had faults. Therefore it must be in what that fuse supplies. It only goes to 2 places - the starter relay and the O2 relay.
If you can pull the wire from F1, start the car and it doesn't blow - you've confirmed its there. I'd be amazed if its not.
As the O2 sensors can cause problems - I'd then put the wire back onto F1 and pull the wire to the O2 sensor from the relay at the relay and try again. Once again if the fuse doesn't go - you've confirmed it is the O2 sensor.
The difficulty will be pulling single wires as these days they all plug in together in a block - so you'll have to find some way of isolating just 1 wire in the block.
Its your decision mate - and I can understand exactly what your thinking - good luck which ever way you turn
Thats a point...Starter relay!
