"Doug" writes:

Before everyone jumps all over Garmin keep in mind that what caused
this was the auxilary fuel tank! It created a condition that the Garmin
unit could not handle. But the stock Cessna setup would never create
this condition! [...]

Given that the fuel vapor return line goes to the left tank, I wonder
what happens on these newfangled 172s if one flies off of the right
tank for quite some time.

- FChE