tds715 said:dude your a tart. it doesn't even cost close to 200 bucks let alone 100.
u can make sure you are nto runnign lean and it help control your af
illusion said:don't be so harsh, and actually the cheasy little A/F monitors folks put in their cars are too narrow of a band to do MUCH good, it bounces around like no tomorrow, to tune your A/F ratio you need a wideband lamda meter. A/F meter's are mostly for looks or to tell you "oops to late". It's just another cool gadget to have around, you'd be better off with a simple volt meter tapped onto the o2 sensor, it would give more accurate readings but would still bounce all over the place. To truely get a picture of your fuel delivery, you need to first have it tuned with a lamda meter and have your fuel curve mapped, then by using an EGT meter and an A/F meter you can "kind of" tell how it's running.
Here if you want to be a bit more accurate
http://www.2gnt.com/www/corbin/dvm2.html . If you figure even the best A/F meters only have 20-25 digit resolution(meaning there are only 20-25 lamps on the meter) with a voltmeter hanging off of the o2 sensor, you have the same resolution as the meter does.
here's a prefab digital
and here's some more
also for the original post, it's pretty easy to find your O2 meter, just start from your headers and go back until you find a little thing sticking out of the side of the pipe with either 1 or 4 wires(possibly 3 if it's grounding through the chassis) on it depending if your O2 has preheat or not.