Air/fuel Ratio Gauge Help!

got an Autometer sport compact A/F ratio gauge....now i know where the red and black wires go, obviously....but the purple wire (signal wire) says to tap into the O2 sensor signal wire...now i've had people tell me to hook it into the ECU for best accuracy. the black is ground and red is suppose to go to ignition switch according to the directions that came with this gauge. but i was also thinking that maybe i should just stick the red into some other power source because the ignition switch is a pain in the ass.....ok so my main question is.....where is the best place to stick all three wires?

thanks for any help

all right i tried these instructions on this page.... http://www.dsmtuners.com/forums/showthread.php?t=69282

when i got the wires all spliced into the ecu, i reconnected the negative terminal on the battery...went to start it, and nothing...when i have the key to the "on" position and try turning on the headlights, i hear a loud continuos clicking and it sounds like it's coming from the ECU...when i turn the key to "off" and turn the headlights on, they're really dim....could my battery just be dead? i don't have another car here right now to jump it...did i mess anything up? i made sure, double checked, and triple checked all of the connections to the ECU and even covered the splices in electrical tape...hopefully it's just something simple like the battery being dead...help!

This might help http://www.plymouthlaser.com/ OR http://www.vfaq.com/FAQlocator-index.html AND maybe try checking www.prostreetonline.com

ok i got the gauge all hooked up and got the car started....now i have another problem....the gauge says i'm running real lean....when i forst start the car, only the first bar on the gauge is lit....after driving and mashing the gas, it never once reaches rich, just jumps from lean to stoich and when i let off the gas, there is nothing (but i think it's suppose to do that)....when i come to an idle, it will go to 1 bar then shut off.....when i leave the accelerator at a certain spot while driving, it'll jump to stoich and then back to nothing.....could it be the gauge that's messed up or my car?

The gauge should only have one or two or three lights lit up at any given time. It should flicker back and forth from the lean side repeatedly. If your car is running as normal, it probably isn't a big deal. On the stock o2 sensor A/F gauges mean very little...

You need to get a wideband O2 sensor for it to really mean anything useful. And Joes right, itll go up and down (or rich to lean) as the car is idle, or running at constant rpm. It should read alil more rich (stock O2) when accelerating.