found a wiring diagram for (i think) my lpg ecu.
Says that violet and grey go to lamba sensor. On my lpg ecu, there is only 1 violet wire so i'll assume thats it. Also GilbertD said about a purple wire. So, there is Violet, a grey wire in next pin and opposite them is violet with a black stripe, and grey with a black stripe. The black striped ones i'd assume are for the opposite side O2 sensor. Again, i can't find anywhere on the loom that they have been spliced in, but it is all inside sheathing and quite well done.
Should i stick it all back together and run it with the lpg ecu disconnected????