<b>First of all, thanks go to Mr D. and UrS4 for their good advice and patience.</b>

<u>Here is how I hooked up the Lascar 1 Volt meter to both O2 sensor wires</u>:

I decided to install the meter and two on/off switches, so that I could monitor both sensors, in the center console wood trim.

1. I removed the wood trim, which on my car is simply snap-on, because I've put away with the screws for easy access a long time ago.

2. I cut two rectangular openings for the two snap-in switches and a 6 mm hole for the meter mount.

3. I prewired the switches for the power source and the O2 sensor leads. I also added a resistor to each positive LED terminal. 330 Ohm for the green LED, 512 Ohm for the red one. The LEDs won't come on when the switches are turned on (they come on with the ignition), but they will make you find the switch in the dark -- and they look pretty. :-P

4. I removed the kick panel under the driver side dash and routed a wire (with inline fuse) from terminal 15 (ignition power) to the center console. I removed the C/C for easy access.

5. I tapped ground at the cigarette lighter.

6. Now I could connect the meter. It worked.

7. I disconnected the battery. Then I deflow...opened the ECU box, pulled the ECU out and tracked down the green wires in the wiring harness (second connector from the right). Following UrS4's suggestion, I used a straight pin to tap the suspected wire. I then used my crappy meter (no decent probes!) to check for continuity between the wire at the ECU and the O2 sensor connector. BTW, I pulled the rubber boot off the top of the O2 sensor connector, and I could clearly see the same green wire! The two pale green wires were the correct ones. I also marked each wire, so that I would know which one was the driver and which was the passeger side sensor. I tapped into both wires with small tap connectors and routed the wires through the convenient opening in the ECU box. I zip-tied the wires carefully and routed them through the center console.

8. I connected the battery.

9. I connected the O2 sensor leads to the switches.

10. I popped the trim back in and installed the driver side kick panel. And that's it.

Not difficult on paper, but all the spine-bending and scraping your hands takes a toll. I'm afraid the neighbor's kid learned a few new words today. ;-)

Does it work? Well, I haven't really tested it yet, but I will post a follow-up soon. Each switch works and the meter does show "something." However, the reading is not steady as I had hoped, but fluctuates pretty rapidly between 0 V and 0.8 V. Not sure yet what to make of it or if it even makes any sense. I'll investigate and hopefully one of you guys will voice an opinion on what I should be seeing. ;-)


<img src="http://pictureposter.audiworld.com/50038/meter1.jpg">
<img src="http://pictureposter.audiworld.com/50038/meter2.jpg">

btw, what are the 3 light switches next to your passenger side butt warmer for? Just curious.

The switches are not being used a switches as all, but the LEDs in them are being used as control lamps. From the right to left:

- right brake light monitor (red LED)
- left brake light monitor (red LED)
- headlights "on" lamp (blue LED)

Remember, it samples every 1/10 sec. Someone correct me if I'm wrong, but it will give you a rough idea at how lean or rich only at higher RPM--cruising and WOT. See if the needle appears more stable at those speeds.

Nice install. I really like that analog-style meter better than the numerical ones.

I ordered one and will see if I can get it anodized in black at a machine shop near my house.

It only happens while in closed loop and is an indication of sampling rates. You learn to average those rapid flickerings/sweeps to give you an idea of "sweep-averaging", that is to say you can mentally average those sweeps and know if you're in the lean-to-rich area of Isostoichiometric.

My high end Fluke Auto meter has a dampening feature that is wonderful in as much as it will take something thats sampling so quickly and average, then display it's samplings at a lower rate. I have a t-tap connector into my A/F meter lead just so I can take it along sometimes to help me know "at a glance" where I'm at ratio-wise. Except for when I'm driving however I'll just watch the meter and do the "mental" averaging.

Welcome to the world of low-tech A/F monitoring. Least you don't have to put up with the disco light show offered by the red/orange/yellow/green and blue on most LED meters. Switch to wide-band and all this "busy-ness" goes out the window. But the price of poker increases exponentially, but then so does the inherent accuracy.

I only drove around the block once, but I thought I could see a "trend," so to speak. I'm sure I'll get used to it and learn how to interpret it. I guess my installation was a sucess. If it's worth the effort, I'm not sure, but hey, it's what we "pioneers" do, right? ;-)

Anodizing it? Won't that cost more than the meter? ;-)

Why do you have your cc on celcius? :-)

because I've been using the metric system all my life. :D