I know a lot of truckers that refuse to buy a Peterbilt just because they put a gauge on everything. The problem, as they see it, is a loose wire, bad sending unit, etc. can sideline a truck. And as we all know, if it ain't runnin', it ain't making payment money...
As I've said many times before, people do this stuff for their own reasons and I really don't care one way or the other. You can put a flashing light on some plastic dog poop and find a whole new market. You see, it all comes down to perceived value. Millions of cars on the road and the vast, vast majority don't have such a gauge, yet for the most part, they do just fine without one. This one was ... an enhancement. It caused a problem. Instantly the 'benefit' was usurped. It turned out the product wasn't at fault, but it wouldn't have been a problem if wasn't there at all.
Mike - by all means, have at it. My initial response was just a little poke in the ribs - nothing more. And by all means, whip out that soldering iron.
Lee - no problemo. Nobody has to walk on eggs around me. As far as the benefit of that particular gauge it might signal something, if you're adept at understanding how to interpret the readings. If it were to suddenly start reading low (or high) that in itself doesn't indicate a bad EGO sensor. It could be a bad MAF, a vacuum hose off, etc. - but these are all things that we would feel anyway. CATs don't melt from lean mixtures, only from rich and that can easily be smelled.