I'm new here but I think I'll jump in.
cool: "Can I buy a California Civic VX with a D15Z motor and put a Lean Burn ECU in it?"
Yes. I did precisely that, with the car I drive daily. But I don't live in CA.
I think it's been mentioned that you also need to swap the O2 sensor.
In a thread at GS (
http://www.gassavers.org/showthread.php?t=4389) I provided very detailed instructions for how to do the wiring without cutting any of your stock wiring.
Unless you also swap the instrument pod, you'll still be missing the SIL (shift indicator light) that was provided only on the Federal model, but there's probably not much reason to care about that.
"What is the easiest way for me to go about this process as I live in California but want a Civic VX with lean burn? "
You might find that the easiest solution is to 'import' a Federal VX from outside CA. Finding a clean VX will be hard, and the first nice one you find might be elsewhere, anyway.
lost: "On GS, one member made the sensor/ECU swap on his VX and still easily passed his CA smog inspection."
I wonder if the comment you're thinking of is this:
http://www.gassavers.org/showpost.ph...5&postcount=43
That situation is a little different than what you described. Anyway, if you can find the thread you're talking about, that would interest me.
diesel: "What is the fifth wire on a wide band"
It might be interesting to notice that the so-called five-wire wideband sensor actually uses an 8-pin connector, and 7 of those pins are used. Two pins are attached to a calibration resistor that is housed in the connector itself. That's why you see only 5 wires traveling from the connector to the sensor.
You can find lots of info about wideband sensors if you google L1H1. The first link that comes up is especially helpful:
http://www.techedge.com.au/vehicle/wbo2/wbntk.htm