legacycentral bbs

Posted: **Tue Mar 02, 2004 12:01 am**

I just need to know which of the 3 wires I tap from the o2 sensor that is going to give my A/F guage some sort of reading.

Posted: **Tue Mar 02, 2004 12:08 am**

You could tap it at the ECU to make the run shorter.

Posted: **Tue Mar 02, 2004 12:21 am**

For me it seems easyer to just tap the O2 wire. Do you know which one is hot?

Posted: **Tue Mar 02, 2004 12:37 am**

Well, one is a ground. One is a heater (12 volts when the car is cold) and the third is signal 0-1 volts or so. You have a volt meter?

Posted: **Tue Mar 02, 2004 12:44 am**

I do. I was just wonding if you had done this before and knew the color to tap into. BTW: I called on a new O2 sensor cause mine looks god awful old, and those people wanted 104 bucks at Autozone. F that.

Posted: **Tue Mar 02, 2004 12:47 am**

Why are you calling any place, didnt you read the 4 wire sensor thread?
http://bbs.legacycentral.org/viewtopic.php?t=14247

Even if you get a 3 wire unit similar to stock with the subaru plug its only 64 dollars from oxygensensors.com
The universal 3 wire is only 44.

Posted: **Fri Apr 23, 2004 6:02 pm**

Just in case anyone else is installing and tapping the ECU my 91 tap was white.

legacycentral bbs

A/F Gauge Install

A/F Gauge Install