A/F gauge with EFIE?
 

I was wondering if anyone here has used an EFIE (if so which kind) and i was wondering wheteher or not it is necassary to use an A/F ratio gauge with it? Will a digital multi meter work just for the voltage? which would you suggest?

My experience with using a digital voltage meter to monitor oxygen sensor output is that the reading jumps around a lot. You can tell if you are running lean, but the numbers are always jumping around.

I get the same result monitoring my O2 sensor output with my Scangauge. The numbers jump around a lot. The only practical application I have found for watching the output is that its easy to tell if the engine is in DFCO, because that's the only time the sensor output = 0.