I use this on my test engine:
https://www.summitracing.com/parts/fst-170402/overview/
The reviews aren't favorable but if you read them you'll understand why [img]<<GRAEMLIN_URL>>/rolleyes.gif[/img]
It's available in single or dual sensor for gas, E85, alcohol and diesel applications
Mine has read rich on my test engine (I've A-B compared it to an Innovative that was used in the dyno cell @ Kammers where I dyno my engines) for a long time, but I attribute this to the fact that the rings in my test engine were SHOT which allowed fuel into the crankcase and oil into the chambers.
This unit has the capability to datalog, but it requires an additional harness & software and also requires a laptop to view the data.
I'll soon be using it both in my Chevelle and in my Malibu wagon--look for an update on that soon.
If you're interested in one of these FAST units, let me know.