I was having intermittent 3 amigos. 2 weeks ago I did the option B fix and I haven't had a problem since. I'm pretty sure I would have had a failure by now if I hadn't done the mod.
Someone on another thread suggested doing the option B fix as a prevention, I just wanted to say that I think that is a good idea. I spent a fair amount of time and bought an ABS Amigo trying to solve it.
In retrospect I wish I had just done the mod and eliminated that pas a potential problem.