Can someone please try to explain this closed loop and I assume open loop, EFI stuff, I'm a bit confused Like what the differences are, is one better than the other?

This is car shit but basically the same.

http://www.enginebasics.com/EFI%20Tuning/Closed%20Loop%20o2.html

Thanks, that helped a fair bit.

More info on closed loop

http://www.nightrider.com/biketech/motorcycle_efi_basics.htm

http://www.rbracing-rsr.com/efiharley.htm

Thanks guys, all very interesting articles, I think I'm starting to get my head around this stuff.