I know there are cheep AFR gauges that are made to work for narrow band O2 sensors.
I am having trouble finding the voltage outputs for the hx (and my first gen insight) sensors. If they were similar, one could easily use this
Sunpro Electrical LED Air Fuel Ratio Gauge NEWCP7011 Authorized Distributor | eBay
They also sell them at some autozones.
With the narrow band sensors they are rather inconclusive, however if they could be made to work with our wide bands they could be uber helpful!
Lol or you can just go buy a wide band O2 from innovative Motor sports like I have on my 91 civic. (However, nullifies the whole cost effective idea.)