Yes, if he has the same problem as I did, the gauge will cut off at a lean value that would actually be lower than what the truck's actual a/f would be. So the truck would be running leaner than the gauge's cutoff point.

But he might try installing it and it might work perfectly.

 

Im gonna see the improvements they make and go from there. It juts sounds like a damn nice saftey feature and there is nothing else out like that at all!