Wideband

wait 15 seconds to build fuel pressure? That goes against the safety feature of an EFI ECU that says "shut pump down after 3 seconds if there is no cam or crank sensor input" Imagine a wrecked car spewing gas at 80 psi out of a broken fuel line? Heated only means it will start to measure faster, burn off carbon sooner and theoretically last longer and go off open loop,reducing emissions. Non heated ran pig rich until the sensor heated up, even if only for a few seconds. It needs to be like 600F to start to measure O2 and it aint gonna make it after the collector unless its heated. Enema O2 probes are self heated. Anolog or needle guages or digi with a fine sweep are much easier to read than a constantly bouncing digi segmented numeric value. Imagine reading a guage that changes every .2 seconds! On a carb, put it off one bank. Youll be measuring both sides of the carb anyway so you can just adjust both sides equally to get an average reading. You can tune one on each side and put a switch on them to measure left then right but that is a bit overkill. Some 4 bangers can run 4 switched off each header leg if they have a 4 channel ECU