my opinion is to do one of these below (second one is better, i will switch to it soon, because it is basically the most accurate way to monitor your O2's) (if someone has a better idea please list it.. because i will be doing # 2 this summer) only thing is you gotta find out what the voltage is for lean-rich so you know where u stand. Hope this helped. Alex L
1. Buy 2 A/F gauges and run them to you O2's so you can meter both at the same time. (most people do one, not sure why with a flip switch, you cant see both readings at the same time when you do it that way, so what good is that ? ) if you set it up like i said you can view both sides at the same time. Thats how i did mine. (but i'm changing to the one below)
2. you could get 2 Wide band O2's and get 2 volt meter gauges (prefferably digital) and hook it up, and view both that way.